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NEW, REVISED AND ENLARGED EDITION 


THE 

Modern Motor Car 

A BOOK OF SIMPLIFIED UPKEEP 

By HAROLD P. MANLY 

U 

! Construction, Care and Adjustment of Motor Car Units, together 
i with Shop and Roadside Methods of Trouble Location and Repair 

HOW TO BUY, MAKE AND USE 
MATERIALS AND SUPPLIES 


Operation and Repair of Electric Engine Starters, Lighting Sys¬ 
tems, Magnetos and Ignition Parts, Electric Brake, Gear Shift, Etc, 

FOR 

REPAIRMEN, OWNERS, DRIVERS, SALESMEN AND STUDENTS 


536 PAGES—225 ILLUSTRATIONS 



LAIRD 4 LEE, Inc., Publishers, = • 

ClAfLx . 


CHICAGO 









Acknowledgment is made of our indebtedness for valuable 
assistance given by the manufacturers of the various automobile 
components treated. 



Copyright, 1914, by Laird & Lee, Inc» 
Copyright, 1918, by Laird & Lee, Inc. 



OCT -9 1918 

The publishers and author will be grateful to readers who will 
be kind enough to make criticisms and suggestions helpful to the 
continued improvement of this book. 


©CLA503780 




INTRODUCTION 


R EPAIRMEN, owners, drivers, students and salesmen 
need an every-day book of reference containing all 
available information applying to their needs, clearly 
and simply written, arranged for the quickest possible use and 
thoroughly covering the subjects of shop and roadside methods 
of repair and adjustment, the use of operating materials and 
supplies, and the construction, operation and care of electric 
lighting, starting and ignition systems. 

The electrical equipment is, for the first time, completely 
treated, including lighting, starting, ignition and control, 
explained in such a way that the average man without elec¬ 
trical experience may be able to properly handle, care for 
and repair every electrical unit. 

Three-fourths of the entire book has been given to the 
following : 

Repair Methods and Practice. 

Troubles and their Remedies. 

Adjustment. Care. Fitting. 

Removal, Replacement, Dis-assembling and Assembling. 

The remainder has been given to a complete, yet brief 
explanation, of the design, construction, type and use of the 
various parts of the car. 

A clear conception of the underlying principles in their 
application to actual practice is first given, preparing the user 
for the following detailed methods and simple rules for making 
correct adjustments and repairs on all parts used in the auto¬ 
mobile. This book has been ^ritten under the conviction that, 
to make it practical, nothing should 'be taken for granted. 
Therefore, every part and operation is explained from the 
ground up, in a way understandable alike to the novice and 
the experienced man. 


The book has been designed, not to compete with the 
general treatises now available, but to furnish a work of refer¬ 
ence for the automobile worker or owner, treating the subjects 
wholly from the standpoint of the man using the car for busi¬ 
ness or pleasure or as a means of livelihood, as a practical 
repairman or operator. 

Every development found in the modern car has been cov¬ 
ered in a condensed form, giving the greatest possible amount 
of information in a book of the most convenient size while 
still retaining full and complete explanation. 

The arrangement is such as allows the quickest possible 
finding of any desired method or fact, this result being accom¬ 
plished by the plan of the subject matter throughout the text 
and through the index which lists every point under all prob¬ 
able and possible headings with complete cross references. 

Some things have been intentionally omitted, these being: 
history and past development, personal prejudice or opinion, 
miscellaneous extracts from magazines and trade papers, 
unimportant matter oftentimes used to produce a large book, 
and details of theory or design interesting only to the student 
of engineering practice. 

The matter presented is the result of eleven years’ work in 
designing, building, operating and repairing gasoline-propelled 
vehicles in pleasure car, truck and motorcycle factories, suc¬ 
cessful garages and repair shops, and in the sales departments 
of factories and distributors. 

Many parts of the work have been used for instruction in 
shop practice for repairmen and drivers, and for all of these 
reasons it is believed that this book will prove of the most 
practical help and profit in everyday use, the feeling that a 
source of practical information is quickly available making it 
a greater pleasure to drive and a more profitable undertaking 
to repair the modern automobile. 

H. P. MANLY. 


VI 


CONTENTS 


For Alphabetical Cross-Jndex see end of volume. 


Introduction 


SECTION ONE 

Motor Car Parts, their Construction, Use, 
Care and Repair,. 


SECTION TWO 

Materials and Supplies, How to Use, Buy or 
Make Materials and Supplies Used in Running 
a Car. 


SECTION THREE 

Electricity—Its Principles Explained, , . . 

SECTION FOUR 

Electric Lighting and Starting. 

SECTION FIVE 

Ignition—Design, Construction, Use, Care and 
Repair of Various Units,. 


PAGE 

1-234 


3-20 


3-28 


1-134 


3-84 


VII 






































































* 





















- 






































» 







































' * I \ 

List of Illustrations 


Section I 

Four cylinder vertical automobile engine.Frontispiece 

Front axle and wheel. 4 

Floating rear axle. 0 

Brace for strengthening rear axle housing. 9 

Annular ball bearing. 13 

Cup and cone ball bearing application. 16 

Solid bearing. 19 

Split bearing . 19 

Oil grooves in bearing. 19 

Connecting rod bearing. 19 

Plain bearing shim. 19 

Clamp for truing shafts. 19 

Hyatt flexible steel roller. 25 

Roller bearing with outer sleeve only. 25 

Roller bearing. 26 

Roller bearing with inner and outer sleeves. 27 

Internal brake . 29 

External brake. 29 

Pull rod with turnbuckle adjustment. 30 

Brake or control pull rods. 30 

Brake equalizers . 31 

Transmission service brake. 32 

Cam and valve opening mechanism. 35 

Miller carburetor. 38 

Holley carburetor used on light cars. 47 

Holley Model “H” carburetor. 48 

Kingston carburetor used on Ford cars. 48 

Kingston carburetor. 49 

Dave Buick carburetor.... 52 

Holley kerosene carburetor . 52 

Schebler Models carburetor.53-57 

Stromberg carburetor, types. 60-62 

Imperial engine primer. 75 

Cross shaft and arms for releasing clutch. 83 

Clutch and brake pedals.. 84 

Cone clutch . 86 

Borg & Beck clutch. 90 

Multiple disc clutch parts. 91 

Points at which compression may be lost. 95 

Effect of bent connecting rod. 97 

Tubular radiator. 100 


IX 












































X 


ILLUSTRATIONS 


Cellular radiator . 100 

Indicator for temperature of water. 102 

Parts that carry ;the power. 106 

Principle of the differential. 115 

- Pine’s radiator shield. 103 

Harrison radiator shutter. 104 

Hudson counter-balanced crankshaft. 110 

'Straightening a bent frame. 130 

Vacuum fuel feed system. 135 

Details of Reo oil pump. 144 

Packard twin six engine. 121 

Removing piston rings. 153 

Modern inlet manifold. 139 

Elliptic springs. 163 

Platform spring . 163 

Worm and sector steering gear. 167 

Air valve for automobile tire. 173 

Tire pressure gauge. 174 

Selective sliding gear transmission. 181 

Sliding gear transmission, end view. 182 

Brake and gear shift hand levers. 183 

Principle of the planetary transmission. 187 

Friction change speed gearing. 192 

Two port, two cycle engine. 201 

Principle of Hotchkiss drive. 178 

Differential piston two cycle engine. 206 

Positions of valve opening and closing. 213 

Inlet, compression, power and exhaust strokes. 213 

Sleeve valve eccentric shaft. 218 

Inlet and compression stroke of sleeve valve engine. 219 

Power stroke of sleeve valve engine. 221 

Rotary valve engine. 222 

Magnetic gear shift. 196-8 

Section III 

Lighting and starting battery. 7 

Flow of direct current. 9 

Series lamp connection. 10 

Multiple lamp connection. 10 

Magnetic field and lines of force. 17 

Electro magnet polarity. 22 

High tension transformer coil. 25 

Principle of the induction coil. 26 

Section IV 

Dynamo mounted in place of magneto. 5 

Warner generator. 7 

Floating the battery on the line. 9 

The flow of water and electricity compared. 10 

Starting motor installation. 13 

Separate unit system. 14 

















































ILLUSTRATIONS xi 

Combined unit system. 15 

Lighting generator with cutout. 16 

Principle of dynamo action. 18 

Field magnets and windings. 20 

Field windings . 21 

Dynamo parts. 22 

Armature coil, commutator and brushes. 24 

Armature windings . 25 

Brush . 26 

Commutator housing and brushes. 28 

Permanent magnet dynamo. 30 

Series field winding. 33 

Shunt field winding. 33 

Compound field winding. 33 

Bucking coil winding. 33 

Combined dynamo and motor. 38 

Overrunning clutch principle. 48 

Typical overrunning clutch. 49 

Starting and lighting wiring diagram. 52 

Broken lamp wires. 53 

Electric side lamp. 54 

Electric tail lamp. 55 

Comparative sizes of lamp bulbs. 56 

Ediswan lamp base. 59 

Trouble-finding lamp. 60 

Lighting systems—one, two, three wire...'.. 63 

Distribution panel and switch housing. 65 

Starting switch...'.. 67 

Circular contact switch. 68 

Switches—various . 69 

Tester for locating faults. 71 

Voltmeter and ammeter connecting. 74 

Three cell storage battery. 77 

Lead cells units. 78 

Interior of storage battery. 79 

Section through lead cell. 80 

Lead cell parts. 83 

Top connections of battery. 84 

Typical starting battery. 85 

Battery testing hydrometer. 86 

Layout of starting and lighting units. 89 

Battery charging. 92 

Arrangement of storage battery interior. 94 

Edison battery .96-100 

Hand operated cut-out. 102 

Centrifugal cut-out. 103 

Electro-magnetic cut-out . 105 

Shunt connected cut-out. 107 

Compound wound cut-out. 107 

Cut-out with weakening resistance coil. 107 




















































Xll 


ILLUSTRATIONS 


Lighting system ammeter. 109 

Output control, shunt field resistance.115-120 

Controller and cut-out. 117 

Wiring of solenoid regulator. 118 

Regulator and cut-out. 119 

Iron wire control. 122 

Bucking coil control. 122 

Controller .123-124 

Constant armature speed control. 125 

Starting motor. 128 

Starting motor on clutch shaft. 129 

Starting motor on transmission case. 129 

Electric brake motor. 130 

Inventor of the electric brake. 131 

Brake controller. 132 

Wiring of electric brake. 132 

Ammeter readings under various conditions. 133 

Section V 

Bosch magneto breaker... 3 

Splitdorf magneto breaker.. 4 

Master vibrator wiring. 7 

Single unit vibrating coil. 9 

Four unit ignition coil. 10 

Four unit coil and timer wiring. 11 

Typical dry cell. 17 

Battery testing ammeter. 18 

Dry cell connections. 20 

Battery connector. 21 

Distributor and timer. 23 

High tension distributor. 25 

Make and break spark coil.., 29 

High tension magneto armature. 34 

Magneto parts . 36 

Waterproof magneto . 37 

Dual magneto . 39 

Magneto inductors . 40 

Armature position. 44 

Magneto breaker, Swiss. 47 

Magneto with breaker cover removed. 48 

Magneto with distributor cover removed...,. 49 

Single or double ignition wiring.•.. 51 

High tension dual magneto wiring. 53 

Coils—-various . 57 

Wiring for magneto with dash coil. 59 

Unisparker .. 63 

Spark plug with one-inch firing surface. 70 

A. L. A. M. spark plug... 71 

Two spark ignition. 75 

Four cylinder timer. 77 

Vibrator and coil parts. 81 




















































SECTION ONE 


Construction, Use, Care and Repair of Motor 
Car Parts. 

Subjects in this section are arranged alphabetically 
under the name of the part. 

Each subject is treated in divisions, the point 
treated being indicated by an initial letter before 
the paragraph. 

The letters and their meanings are as follows: 

D. Design, Use and Construction. 

C. Care Required. 

A. Adjustment Methods. 

R. Removal and Replacement. 

T. Troubles and Repair Methods. 







AXLES. 


Front Axle. D. Front axles are made in four de¬ 
signs, the commonest being an “I” Beam section, next 
in order of use being the solid round, square or hex¬ 
agonal type. Less used types are the hollow tube and 
another type formed by two channel pieces placed 
together to make a box-like enclosure. 

Axles of the first two designs are made from steel 
drop forgings, tubular axles are of seamless steel and 
the channel axles have the parts pressed to shape 
while cold. 

C. The long vertical bolts holding the steering 
knuckles into each end of the front axle must be kept 
parallel to each other and they must stand exactly 
vertical when looked at from the front of the car. 

The spindles on which the front wheels turn should 
be bent down at the outer end so that the point at 
which the tire rests on the road will be almost, if not 
quite, underneath the vertical knuckle bolt. This 
makes the car steer easily. 

A. Should the axle not meet the above conditions 
the bent parts should be heated dull red and carefully 
bent to correct shape. 

R. In reassembling the front axle with its steering 
knuckles and the cross tie rod, the knuckles should 
first be placed on the ends of the axle and the long 
bolts put in place. The tie rod should then be attached 
with its bolts. As each part is fastened in place make 
sure that it moves freely. 

T. A bent front axle causes hard steering and wears 
the tread from one or both front tires very rapidly. 

For explanation of letters appearing before paragraphs see 
page one. 

3 


2 


Section 1 

4 


MOTOR CAR PARTS 


An axle thought to be bent should be run over a level 
floor or else over a straight bar and the position of the 
bolts and shape of the axle tested with a steel square. 
Bent axles, if not too much out of line, may be 



straightened by placing the base of a jack against the 
high part and running a chain over the top of the jack 
and fastening the ends of the chain to the axle ends. 

A bent axle may also be straightened by fastening 
a long bar to the axle, wrapping a chain around the 











MOTOR CAR PARTS 


Section 1 

5 


axle and bar. The axle may then be caught between 
any two solid posts or supports and pressure applied 
to the end of the bar to straighten the axle. 

Rear Axle. D. Rear axles are divided into “Live 
Axles” in which the shafts are carried inside a tubular 
housing, the center of the housing being large enough 
to carry the differential and bevel gears; or “Dead 
Axles” which are solid from end to end, the wheels 
being driven by chains. 

Live axles are divided into three classes in common 
use today. 

“Full Floating Rear Axles” have the differential car¬ 
ried on bearings in the housing, the road wheels being 
mounted on two bearings in each hub which run on 
the outside of the ends of the housing. The driving 
shaft is stuck into the differential at the inner end and 
the outer end of this shaft is carried by a two, four or 
six jawed clutch. The axle end passes into a hole in 
the center of the clutch and the jaws of the clutch 
mesh into teeth in the hub of the wheel. The shaft 
thus carries no load. 

“Semi-Floating Rear Axles” have the differential 
carried on bearings in the housing, the inner end of 
the driving shaft being stuck into the differential. The 
outer end of the driving shaft is carried on a bearing 
inside the end of the housing and the wheel hub is 
fitted onto the end of the driving shaft. The wheel is 
held on by nuts or pins, the end of the axle shaft being 
tapered, squared or keyed. 

“Three Quarter Floating Axles” have the differential 
carried on bearings in the housing, the inner end of 
the driving shaft being stuck into the differential. 
The road wheel is carried on a single bearing on the 


Section 1 
6 


MOTOR CAR PARTS 


outside of the end of the housing, the wheel hub fit¬ 
ting over this bearing. The driving shaft extends 


.1 

[jgp 

L i 

Semi 

F/oating 



Fu// r/gating 



Three Quarter Floating 

THREE TYPES OF LIVE REAR AXLES. 


through the housing to a point outside the wheel and 
carries a large plate at its outer end. This plate bolts 




















MOTOR CAR PARTS 


Section 1 

7 

to another plate fastened to the wheel hub so that the 
shaft is supported by the wheel and the wheel is pre¬ 
vented from turning out of true or wobbling by the 
driving shaft. When the wheel is placed on the axle 
the depression in the plate on the wheel should face 
outward. The bearing is then slipped into this de¬ 
pression from the outside and fastened with nuts on 
the housing. The driving shaft is then pushed into 
place in the differential bringing its flange plate into 
position for bolting to the hub. 

An old and little used type called a “Live Axle” has 
the driving shaft carried in a bearing at each end of 
the shaft inside the housing. The differential is then 
carried by the inner end of the shaft and the road 
wheel by the outer end. 

C. Rear axles should be filled to a depth of 1% to 
3 inches with very light transmission grease or with 
cylinder oil. The housing at the center should be 
filled only to a point at which the large bevel gear will 
dip into the oil or grease. Never pack an axle full of 
grease. 

A. The driving bevel gears may become noisy by 
not being properly meshed. To make this adjust¬ 
ment— 

Block up the rear of the car so that both rear wheels 
are off the floor. Start the engine, place the gears in 
high speed and let the clutch in. Now make sure that 
the noise is in the rear axle and not in the transmission, 
the engine gears, or other parts of the car. 

The bearing just in front of the small bevel driving 
pinion should have means for throwing the pinion back¬ 
ward or forward in or out of mesh with the larger 
gear. Set the small pinion backward or forward a 


Section 1 
8 


MOTOR CAR PARTS 


very little at a time until the noise disappears. If the 
noise does not disappear replace the small bevel in the 
same position as when you started. 

The bearing carrying the bevel gear side of the 
differential should have means for throwing the 
differential slightly to the right or left. This may be 
done, a very little at a time until the noise disappears. 
In case this bearing has no adjustment the washers 
may be removed and thinner ones put in, or else thin 
brass shims may be placed between the bearing and 
differential case. 

In some cases both pinion and gear may have to be 
adjusted, but if this does not correct the trouble, the 
gears are too badly worn or are loose on the drive 
shaft or differential case or the differential runs out 
of line or the bearings may be loose or worn out. 

R. In reassembling a rear axle each part should be 
tried as it is placed in position to see that it turns 
freely. 

All housing joints should have paper gaskets well 
shellaced and should be bolted tight. 

T. The rear axle housing carries the springs on 
spring seats which may be designed to turn on the 
axle housing, being in the form of a bearing and 
having a grease cup. Looseness at this bearing causes 
a loud knock when the car is driven off a bump in the 
road at fair speed. This bearing should be treated 
like any other plain bearing in adjustment required. 

If the rear axle housing leaks oil at the wheel ends 
so that the brakes, hubs and even the wheels and rims 
become covered with oil or grease the trouble is 
probably that the housing has been filled too full of 
oil. This may be corrected by first draining the grease 


„ Section 1 

MOTOR CAR PARTS 9 

or oil to the proper level, removing the wheels and 
washing the grease from all exposed parts and re¬ 
moving it from the brake linings as directed under 
“Brakes.” 

The driving shaft should be removed and the grease 
washers or packing or drain tubes should be cleaned 
or replaced. Should the axle still leak oil or grease 
the wheel may be removed and the bearings inside 
the outer end of the housing taken out and about a 
pound of waste stuffed into each end of the axle. 



BRACE FOR STRENGTHENING REAR AXLE HOUSING. 

Full floating axle loose wheels may be tightened 
by adjusting the wheel bearings as directed under 
“Bearings.” 

Full floating axles having play in the wheel jaw 
clutches make a rattling noise at the rear of the car. 
The best remedy is to fit new clutches or new hubs 
or both, but a very good repair may be made by heat¬ 
ing the clutches slowly to a red heat and hammering 
them out so that they will take up the play. The 
clutches should then be tempered and the driving faces 
case hardened, after dressing to an exact fit. A tem¬ 
porary repair may be effected by placing thin sheets 


Section 1 
10 


MOTOR CAR PARTS 


of brass shim stock between the clutches and hub teeth. 
Thin steel would make a more permanent job. 

Semi-floating axles often have the driving shaft 
bent by skidding, hitting the curb or going over bumps 
too hard. To remove the shaft take the wheel off the 
end, remove the bearing inside the end of the housing 
and pull the shaft out of the differential. To remove 
the wheel first take the hub cap off, then remove or 
loosen the cotter pin, straight pin, or other locking 
device for the nut, then take off the nut (which may 
have either a right or left hand thread) and then try 
to pull the wheel off by hand. 

If the wheel does not come off, catch the jaws of a 
wheel puller over the edges of the brake drum and 
place the point of the screw in the small hole in the 
center of the end of the axle. 

In replacing the wheel turn the driving shaft until 
the keyway is on top, lay the key in the keyway and 
slip the wheel on the shaft, holding the keyway in the 
hub uppermost. It is a good idea to slightly oil the 
end of the shaft before replacing the wheel. 

Three quarter floating axles, being a combination of 
the other two types may have some of the troubles of 
each as well as having some of the advantages and 
some of the disadvantages of each. 


BALL JOINTS. 


D. These joints allow movement in any direction, 
and are made up of a steel ball which slips into the 
end of a tubular piece. The neck of the ball passes 
into a slit cut along one side of the tubular piece and 
the ball comes up against a spherical end of the tube 
on the inside. A plug is then screwed or slid into the 
tubular piece, closing the end through which the ball 
passed. This plug is cup shaped at the end touch- 
ing the ball. If the plug slips into the tube there is 
a screw plug that follows it and holds it in place. 
Some ball joints have short, heavy coil springs placed 
back of the cup ended plugs. 

Ball joints, or ball and socket joints, are used for the 
rod from the front axle to the arm on the steering gear 
and for the radius or distance or torsion rod ends in 
some cases. Small ball joints are used on the rods 
operating the spark and throttle controls and for any 
other small control rods on the car. 

C. Ball and socket joints should be lubricated with 
cup grease and the larger types should have leather 
covers placed around them and strapped on. 

A. Ball joints are adjusted and play is removed by 
screwing the plug farther into the end. The plug is 
prevented from turning by a cotter pin,, straight pin 
and ring, or taper pin. These pins must first be re¬ 
moved and they must be replaced after the adjust¬ 
ment is made. 


11 



Section 1 
12 


MOTOR CAR PARTS 


T. After long use the ball may become flattened, 
making a new one necessary. Another trouble is that 
the tubular piece is worn to such an extent that the 
slot is large enough so that the ball can slip out of the 
side. The tubular end must be replaced with a new 
one as this is a dangerous condition. 


BEARINGS. 



Annular Ball. D. An annular ball bearing is com¬ 
posed of a circle of steel balls enclosed between an 
outside and an inside ring. The inside ring is made 
to fit over the shaft to be supported and has a slight 


ANNULAR BALL BEARING. 

groove cut around it for the balls to roll in. The out¬ 
side ring fits into the housing or part supporting the 
shaft, and this ring has a slight groove around its in¬ 
side surface for the balls to roll in. These rings are 
made of hardened steel and are called the inside and 
outside race. The balls are sometimes separated from 

13 



Section 1 

14 MOTOR CAR PARTS 

each other by small springs or pieces of metal or the 
balls may be held in a certain position relative to each 
other while rolling by metal cages in the form of a 
ring. 

Annular ball bearings are most suitable for a radial 
load or one coming at right angles to the shaft. They 
will also support an end load of about one-fifth the 
radial load. 

Some annular bearings have one row of balls between 
the two races and are called “single row annular bear¬ 
ings,” while others have two complete rows of balls 
between the two races and are called “double row an¬ 
nular bearings.” 

Annular bearings are also made with the outer race 
made of two separate rings fitting one inside the other. 
The joint between the two parts is of spherical shape 
so that the inner part of the race can turn in any direc¬ 
tion in the outer part and yet be held tightly. This al¬ 
lows the shaft carried by the bearing to run smoothly 
even if it is not exactly in line with the bearing sup¬ 
port, or a bent shaft will run smoothly in this type of 
bearing. They are called “self aligning annular ball 
bearings.” 

Annular bearings are used where the friction must 
be very small. They have been used at every point of 
an engine and car. They are suitable for use in the 
engine, clutch, transmission, front and rear axle, differ¬ 
ential, steering gear, wheels, etc. 

C. The annular bearings should be packed with 
vaseline or light transmission grease of high quality 
when in the wheels, axles, steering gear, magnetos, etc. 
When in the engine, transmission or differential, they 
are oiled by the oil or grease used in these parts. 


MOTOR CAR PARTS 


Section 1 

15 

Annular bearings are not adjustable, the only way 
of taking up wear is by taking them apart and grind¬ 
ing the races to the correct shape and fitting new and 
larger balls. This cannot be done in the ordinary shop 
but the bearings will have to be sent to a ball bearing 
repair house. 

When an annular bearing allows you to feel an up 
and down play between the two rings or when the 
rings can be moved sidewise for 1/25 of the bearing 
diameter they are loose enough to cause rattling or 
knocking and should be reground or replaced with 
new ones if used at a point where slight looseness is 
undesirable. 

R. Annular bearings are removed by first taking off 
whatever locking nut or washer holds the bearing from 
moving endwise on the shaft and then sliding the 
bearing off the end of the shaft. This sliding may take 
some force inasmuch as annular bearings are made 
to fit snug both on the shaft and in the holder. How¬ 
ever, they should be easily removed if started straight 
without wedging or jamming. 

In replacing annular bearings first be sure that the 
bearing is free of dirt and grit by washing thoroughly 
in kerosene or gasoline. Then lubricate the bearing 
around the balls and in placing the bearing on the 
shaft or in the holder be sure that it does not wedge 
in any way and that it stands square on the shaft and 
in the housing while sliding into place. 

Annular bearings usually have felt packing washers 
at one or both sides of the bearing which are held in 
place by thin metal rings called dust washers. These 
washers of felt should fit tightly around the shaft and 
into the housing in order to prevent the leakage of 


Section 1 
16 


MOTOR CAR PARTS 


grease or oil. New or clean washers should be used 
or the old ones should be washed with gasoline. In 
some cases two or three washers may be required to 
make a tight joint if there is room for the extra thick¬ 
ness. 

Cup and Cone. D. This is a cheaper type of ball 
bearing than the annular type. It is made by having a 
ring or race to fit over the shaft to be carried, this race 
being in the shape of a cone on which the balls roll. To 
hold the balls on the face of the cone there is a cup¬ 
shaped outer race which fits over the balls and this 
outer race fits into the housing or bearing holder. In 



CUP AND CONE BALL BEARING APPLICATION. 

the case of a wheel the cup-shaped outer race is held 
in the wheel and the cone is in the form of a nut that 
screws onto the end of the shaft. The balls are placed 
in the cup and the cone holds them in place while 
rolling. 

Cup and cone bearings are used on front wheels of 
light cars, on cooling fans, and places where the load 
is light. 
















MOTOR CAR PARTS 


Section 1 

17 


C. Cup and cone bearings are lubricated with vase¬ 
line or a high grade, light bodied transmission grease. 
They should be kept clean and free of grit and dirt. 

A. This type of bearing is adjusted by placing the 
wheel or other part on its shaft and filling the cup with 
grease. The balls may then be stuck into this grease 
and it will hold them in place while the cone is screwed 
or pushed over the end of the shaft. If the cone is not 
threaded inside there will be two locking nuts to go 
on outside the cone and even if the cone is threaded 
there will be one nut to lock it. Screw the cone and 
nut up tight enough to hold the wheel so it can turn 
but not tight enough to prevent play or shake. Now 
whirl the wheel and with it whirling slowly tighten the 
cone until the extra friction stops the wheel from turn¬ 
ing easily. Now turn the nut or cone back just far 
enough to let the wheel or part turn freely and lock in 
this position. 

T. Worn cup and cone bearings can be detected by 
examining the balls, the cup and the cone. If any of 
them show pitting or grooves they should be replaced 
with new parts, as a worn cup and cone bearing may 
break and cut off the shaft on which it turns. 

Plain Bearings. D. Plain bearings include all forms 
made without the use of balls or rollers and in which 
the motion is a sliding one in place of rolling. 

Plain bearings are made of various metals and are 
in the form of short sections of tube-like form that sur¬ 
round the shaft to be carried and are set into some 
form of housing or bearing holder. They are some¬ 
times split into two halves so that the bearing may be 
placed around the shaft at any point or they may be in 
one solid piece when they have to be slipped over the 
end of the shaft. 


Section 1 
18 


MOTOR CAR PARTS 


Plain bearings are made from babbitt metal, white 
metal or white bronze, brass, bearing bronze and in 
rare cases from cast iron. Babbitt bearings are poured 
into place; white metal bearings are made by die cast¬ 
ing and must be secured from the makers of the part; 
brass or bronze bearings are made from bars by lathe 
work. 

Plain bearings have been used at every point in the 
car, even in the wheels of old cars. They are gradu¬ 
ally giving way to the use of ball and roller bearings, 
but are still almost always found on the connecting 
rods, wrist pins, crank shaft bearings and cam shaft 
bearings. They are often used in the transmission and 
steering gear also. The axles and wheels are usually 
fitted with ball or roller bearings. 

C. Plain bearings must always be kept properly ad¬ 
justed, as a little looseness soon becomes much worse 
and may easily cause serious damage to the shafts or 
breakage of parts. Plain bearings also require much 
more care in lubrication than ball or roller bearings, 
about 10 to 30 seconds being the limit that a plain 
bearing will run without lubrication. 

A. When a one-piece or solid plain bearing develops 
wear and looseness which is at all noticeable when the 
bearing or shaft is lifted up or down, it must be re¬ 
placed with a new bearing. Plain solid brass or bronze 
bearings may be turned out to an inside diameter about 
% to t 3 6 inches larger than the shaft they carry, and the 
bearing may then be filled with babbitt. The bearing 
should be replaced whenever possible, however. 

When bearings are made in halves the parts of the 
bearing metal are carried in housings or boxes made of 
steel, brass, iron or bronze. These housings are then 
bolted together around the shaft so that the bearing 


MOTOR CAR PARTS 


Section 1 

19 


metal is supported all around by the stronger housing. 
The main or stationary part holds one-half the bear¬ 
ing and the removable part or cap holds the other half. 



PLAIN BEARINGS, THEIR APPLICATION AND CARE 


Some plain bearings are made with the halves 
slightly separated and having very thin pieces of brass 
between the edges of the halves. These pieces are called 
“shims” and there may be a number of them on each 
side of the bearing. 

































Section 1 
20 


MOTOR CAR PARTS 


As the bearing wears, the halves may be brought 
nearer together by taking off the cap and removing the 
thinnest shim from each side and then replacing the 
cap and trying the play. If the bearing is then too 
tight one shim or else thinner shims must be replaced. 
When shims are used you must be sure that the metal 
of the shim covers the cap entirely and also comes tight 
up against the shaft, entirely covering the edges of the 
bearing metal pieces. 

Shims should be removed until the bearing will not 
turn on the shaft, then one or two very thin shims 
should be replaced so that the shaft will just turn, but 
without play. An even thickness or number of shims 
should be removed from each side of a bearing. If 
there are no shims or if the bearing is still loose after 
removing all the shims the halves may be brought 
closer together by placing the bearing cap in the vise 
under very light pressure so that the bearing will not 
be forced out of shape. With a long flat mill file, some 
metal is then removed from the edges of the cap by 
filing straight across, touching both sides evenly and 
removing an even amount of metal all across. This 
may be easily done by holding the left hand on the file 
over the bearing and using the right hand only for 
moving the file, or the file may be laid flat on the 
bench and the bearing cap rubbed along the file, press¬ 
ing evenly on both sides. , 

After removing a small amount of metal from the 
cap the same process should be gone through with on 
the other half of the bearing. The parts should then be 
bolted around the shaft and the fit tested. Continue 
this filing until all play disappears, leaving the shaft 
free to turn. If too much metal is removed make a 
very thin shim for each side of the bearing. 


MOTOR CAR PARTS 


Section 1 
21 


While the above methods will remove the play tem¬ 
porarily, they do not make a true fit around the shaft 
for the reason that they take up only the endwise play 
and do not bring the sides of the bearing any nearer the 
shaft at the edges of the pieces. 

Bearings are properly adjusted and fitted only by 
scraping to an exact fit. 

Scraping requires the use of a “bearing scraper” and 
“Prussian blue,” also great care in the work. 

A bearing scraper handle should be held loosely be¬ 
tween the fingers of the right hand and the cutting 
edges of the scraper should lie in the half of the bear¬ 
ing being scraped. The blade of the scraper is lightly 
pressed onto the bearing surface by the fingers of the 
left hand and by turning the scraper with the right 
hand a very small amount of metal may be removed 
from any part of the bearing surface. 

First remove the bearing cap and the halves of the 
bearing so that the shaft is exposed. If the shaft is 
rough or pitted or has rings cut around it, the surface 
must be made smooth, as directed below. If the shaft 
is perfectly smooth and round take a very little Prus¬ 
sian blue on the tip of the finger and rub it all around 
the surface of the shaft where it touches the bearing, 
making a very thin, even layer of the blue. Now re¬ 
move enough shims or file the holders so that the play 
is removed and then bolt the bearing to the shaft. Turn 
the shaft or bearing once or twice around and then 
remove the bearing. Wherever the bearing touched 
the shaft the bearing surface will be blue. 

Now place the bearing in the vise and with the 
scraper remove a very thin layer of metal wherever it 
is blue and then wipe all the Prussian blue off both 


Section 1 
22 


MOTOR CAR PARTS 


sides of the bearing with a clean cloth. With the fore¬ 
finger rub the Prussian blue evenly over this (journal) 
shaft again so that the surface of the (journal) shaft 
has a very thin and even coat of the blue. Do this with 
both halves of the bearing and then replace the bearing 
on the shaft and tighten the bolts. If play is present 
remove more shims or file the housing more and again 
turn the shaft or bearing. 

Remove the bearing once more and scrape carefully 
wherever the blue shows. Add more blue to the shaft 
if necessary and repeat this operation until about two- 
thirds of the bearing surface comes off blue. This blue 
should show in an oval shaped patch around the center 
of the bearing. 

After the bearing is properly scraped wash off all the 
blue with gasoline, cover the bearing and shaft with 
cylinder oil and replace the bearing on the shaft. While 
tightening the bolts for the last time it is best to strike 
the bearing lightly with a hammer as this makes the 
bearing fit tight to the shaft. 

Be sure that the shims extend right through to the 
shaft so that the bearing metal will not turn inside the 
cap and holder. 

Also be sure that every nut and bolt is locked in 
place with a cotter pin, double nut, wire through the 
bolt head, or special lock or whatever means has been 
provided for holding the nut or bolt. Never depend on 
a lock washer to hold bearing bolts inside the parts of 
the car. Neglect of tightening and locking bolts and 
nuts has been the cause of many wrecked engines. 

R. Plain bearings must have some means of getting 
oil into the bearing aside from what would work in 
from the ends. To accomplish this, holes are drilled 


Section 1 

MOTOR CAR PARTS 23 

through the center of one or both halves of a split bear¬ 
ing or in the top or bottom of a solid bearing. Care 
must be used to see that these holes are not stopped up 
and that the hole in the bearing metal exactly matches 
the hole in the cap or holder through which the oil or 
grease comes. 

Starting from this oil hole there are small grooves 
cut into the surface of the bearing that lead toward the 
edges. Sometimes they go right to the edge, some¬ 
times they end a half or quarter inch from the edge, 
their purpose being to distribute the oil. White metal 
and babbitt bearings require these grooves about one 
inch apart; brass and bronze should have them about a 
half inch apart. Care should be used to see that these 
grooves are free and open before reassembling the 
bearing. 

When plain bearings are used where the shaft ex¬ 
tends through the case and bearing in such a way that 
the oil might be forced out of the case through the 
bearing some means must be taken for preventing this 
leakage. 

In plain bearings this usually takes the form of a 
deep groove cut all the way around the inside of the 
bearing near the outer end. There is a small hole 
drilled through the bearing into this groove and on 
the bottom. This hole leads back into the crank case, 
transmission case, axle housing, etc., so that oil pass¬ 
ing out of the. bearing is caught in the groove and 
returned. 

An extension of the case is sometimes carried out¬ 
side the bearing so that oil may be caught in the ex¬ 
tension and returned to the case through a tube. 

T. Should the shaft on which a plain bearing is 


Section 1 

24 


MOTOR CAR PARTS 


mounted become rough or pitted or scratched it may 
be turned down in the lathe to a smooth surface. 

Another method of securing a smooth surface is to 
take two pieces of wood about 1% by 2y% inches and 
2. feet long. Lay these pieces with the narrow edges 
touching and around the outside of one end screw a 
strap so that the pieces are hinged together. Still hold¬ 
ing the pieces together, cut a hole so that half the hole 
is in each piece, this hole to be about 3 inches from one 
end and of the same diameter as the shaft to be treated. 
Tack a medium grade of emery cloth to the wood pieces 
so that the cloth fits around the halves of the hole with 
the emery side away from the wood. Now clamp this 
around the shaft with the hands so that the emery 
touches the rough part. Apply some pressure by hold¬ 
ing the free ends of the wood pieces together while the 
shaft is turned in the car or while mounted between 
the lathe centers. In a short time this action will 
bring the surface of the shaft smooth, although it will 
not necessarily make it perfectly round. 

Roller. D. A roller bearing is composed of a circle 
of steel rollers enclosed between an outside and in¬ 
side ring. The inside ring fits over the shaft to be sup¬ 
ported and the outside ring fits into the housing or tube 
that carries the bearing. These rings are made of 
hardened steel and are called th.e inside and outside 
races. The rollers may be prevented from touching 
each other by having their ends carried by some form 
of metal cage or retainer that holds them the proper 
distance from the roll at each side while they roll 
between the races. 

Some forms of roller bearings are made so that the 
rollers rest directly on the shaft without the use of 


, , ^ „ Section 1 

MOTOR CAR PARTS 25 

an inner race, others are made so that the rollers fit 
inside the housing without the use of an outer race. 

The rollers may be of solid steel or they may be 
formed from thin flat steel twisted into a spiral roll. 



HYATT FLEXIBLE STEEL ROLLER. 


These are called flexible roller bearings. 

Solid rollers may be made either straight or tapered, 
the races of course being straight or tapered accord¬ 
ingly. 



ROLLER BEARING WITH OUTER SLEEVE ONLY. 


Roller bearings have been used at every point of 
the automobile except the connecting rod and wrist pin 
bearings, but are found principally in the transmission, 
rear axle and wheels. 




Section 1 
26 


MOTOR CAR PARTS 


C. All forms of roller bearings should be packed with 
vaseline or a light bodied high grade transmission 
grease if used in wheels, axles, steering gears, etc. If 
in the engine or transmission case they will be oiled 
with the grease or cylinder oil used in these parts. 

Taper roller bearings must be kept properly ad¬ 
justed, clean and free of all forms of dirt. 



0 ; 


m 


ROLLER BEARING. 

A. Flexible roller bearings and straight solid roller 
bearings are not adjustable. Taper roller bearings 
and straight rolls having a flange around one end are 
adjustable by screwing the nut tighter that holds the 
bearing onto its spindle or shaft. 

After placing the bearing parts in place leave them 
slightly loose and whirl the wheel or part carried by 















Section 1 

MOTOR CAR PARTS 27 

the bearing and while it whirls turn the nut tighter 
and tighter. When the tightness prevents easy turn¬ 
ing of the bearing bring the nut back just far enough 
so that the parts turn easily, but without play. 

Great care should be used that roller bearings are 
not made too tight as this will cause them to cut and 
wear very rapidly. 

The nut that holds the roller bearing onto the end of 
the shaft must be locked in position by an extra nut, 
pin or a special washer. 

T. Roller bearings become loose, broken or worn 



ROLLER BEARING WITH INNER AND OUTER SLEEVES OR RACES. 

from several causes. These include wrong or insuffi¬ 
cient lubrication, too tight adjustment, not being a 
proper fit for the shaft or housing, or from being dirty. 

Roller bearings usually have felt packing washers 
at one or both sides for the purpose of preventing 
leakage of oil or grease. These washers are held in 
place by metal rings that keep the felt tightly around 
the shaft and against the housing. New washers* 
should be used or the old ones should be washed in 
gasoline. Two or more washers may be required if 
the space is large enough to take them. 


BRAKES. 


D. Brakes are of two general types. Each type acts 
on a steel rim or drum fastened to the spokes or hub 
of the road wheels or to the drive shaft. An “External 
Contracting” brake is formed by a thin metal band ex¬ 
tending around the outside of the drum with levers 
arranged to draw the band tight enough to stop the 
motion of the drum. An “Internal Expanding” brake 
is formed by a shoe or two shoes inside the drum. By 
a cam or lever arrangement these shoes are pushed 
apart, exerting enough pressure on the drum to stop 
its rotating. 

Both external and internal brakes are usually faced 
with an asbestos fabric called brake lining. The in¬ 
ternal brakes are often formed of plain cast iron shoes 
without the lining. 

One of the brakes, outside or inside, is connected to 
the foot pedal and is called the service brake; the other 
brake being operated by the hand lever and called the 
emergency brake. 

C. Both brakes should be kept properly adjusted 
and free of dirt, oil or grease at all times. 

A. To adjust either type of brake, the rod that pulls 
the brake is usually made with one clevis or yoke end 
threaded onto the rod. By removing the clevis pin 
and screwing the clevis onto or off the rod the 
brakes may be tightened or loosened. Many other 
forms of adjustment are provided, all designed to draw 
the band tighter or expand the shoes more while the 

28 


MOTOR CAR PARTS 


Section 1 

29 


pedal or hand lever remains at the same position. 
These adjustments are usually operated by some form 
of screw or nut which draws the ends of the bands 
tighter and closer or expands the shoes closer to the 
drum. To properly adjust brakes— 

1st—Jack both rear wheels clear of the floor and 
place the car on solid blocking. Start the engine, and 
with the gears in low speed let the clutch in. 

2nd—Apply the brake to be adjusted very slowly and 
notice which wheel stops first. 



3rd—The brake that was operated (outside or in¬ 
side) should be tightened on the wheel that stopped 
LAST and the test repeated until both wheels stop 
practically at the same time. 

4th—Place the gears in second speed and with the 
clutch engaged open the throttle slowly while apply¬ 
ing the brake harder and harder. As you apply the 
brake open the throttle more and more until it is wide 
open. The brakes should be strong enough to stop 
the engine with the throttle wide open. 

5th—After tightening the brakes sufficiently, stop 




Section 1 

30 


MOTOR CAR PARTS 


the engine and place the gears in neutral. The wheels 
should now turn easily by hand without resistance 
from the brakes. 

If the brakes cannot be made to hold according to 
the above without dragging when released they need 
relining or else are greasy or dirty or the operating 
parts are loose or binding. 

The brakes should never be applied suddenly or 
hard enough to slide the wheels on the road. A car 
will not stop as quick with the wheels sliding as with 
them turning. 



BRAKE OR CONTROL PULL RODS. 

Showing the clevis ends with their pins, these ends screwing onto or off 
from the rods giving adjustment for length. The length may also be adjusted 
by the turnbuckle on the upper rod. 

T. To Replace Worn Facings on Brake Bands or 
Shoes— 

1st—Remove all the old lining by cutting off the 
rivets with a chisel. 

2nd—Secure the necessary length of new lining of 
the same width and thickness as the old lining. In 
case the drum shows excessive wear and is quite thin, 
lining l/16th of an inch thicker may be used. Also 
secure enough copper rivets to fill each of the old holes. 

3rd—Hold one end of the new lining at the end of 
the shoe or band and drill through for the first two or 
three rivets, but do not cut the lining off yet. 




Section 1 

31 


MOTOR CAR PARTS 


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Section 1 

32 


MOTOR CAR PARTS 


4th—Select a drill of the same diameter as the head 
of the rivets and grind it until the point is almost flat. 
With this drill cut about half way through the lining at 



LOCATION OF FORD SERVICE BRAKE IN PLANETARY GEARBOX 


the rivet holes so that the head of the rivet can sink 
below the surface of the lining. 

5th—Place the end of the lining back on the band or 
shoe and push the first two or three rivets into place 
but do not fasten them. Now pull the lining tightly 
into place and with a prick punch mark the rest of the 
holes for rivets. 

6th—Drill and countersink the balance of the rivet 







MOTOR CAR PARTS 


Section 1 

33 


holes, rivet the lining in place and cut it off the proper 
length with a hack saw. 

To Remove Grease from Asbestos Brake Lining— 

1st—Remove the band or shoe from the wheel and 
hold it in the vise. 

2nd—Direct the flame from a gasoline or acetylene 
torch onto the lining until all the grease is burned out 
and there is no more yellow flame. 

All brake operating parts should move freely with¬ 
out binding. However, they should not be so loose 
that the play prevents the brakes from taking hold 
properly. 

The Transmission Brake. Another type of brake 
which finds frequent use in both low-priced and high- 
priced cars is the transmission brake. Probably one of 
the most typical examples of this construction is found 
in the Ford car. Here the transmission brake serves as 
the service brake and the rear axle brake is used only 
as an emergency medium. 

The transmission brake, in conventional construc¬ 
tions, is a band contracting onto a drum which is a part 
of the driving line between the engine and the rear axle. 
This brake is clearly shown in the illustration. In the 
case of the Ford, as illustrated, when the pedal is pushed 
forward it constricts an asbestos fabric-lined brake 
band around the drum that also forms the casing for the 
multiple-disk clutch assembly. As this drum is part of 
the assembly to which the propeller shaft is attached 
and as this, in turn, controls the rear wheels through 
the medium of the bevel pinion carried at its lower end, 
whenever the transmission assembly is clamped by this 
brake band the movement of the rear wheels must 
necessarily be retarded. If the pedal is pushed hard 


Section 1 

34 


MOTOR CAR PARTS 


enough the friction created will be so great that the 
rear wheels cannot turn and must come to a stop, even 
on a steep hill. 

The adjustment of a brake of this type is a very 
similar process to the adjustment of rear-wheel con¬ 
tracting brakes. The operation consists of tightening 
the band whenever enough wear has taken place to 
make the operation of the brake unsatisfactory. In the 
case of the Ford the brake adjusting nut is turned down 
against the spring, shown in the illustration, until the 
bands are sufficiently contracted so that the brake will 
again perform its function in the proper manner. 

One of the things to watch out for in making such an 
adjustment is to contract the bands just enough and 
not too much. If the bands are contracted sufficiently 
to cause a constant drag when the brake pedal is in its 
normal position the drum will heat, there will be a loss 
of power and consequent increase in the consumption 
of the gasoline, and the bearings are liable to suffer. 


CAMS. 


D. Cams are circular pieces of metal having one 
side higher than the other and which in turning on a 
shaft bring the high side around once every revolution. 
In modern engines the cams are usually made in 



one piece with the cam shaft and are said to be in¬ 
tegral with the shaft. That part of the shaft that fits 
into the bearings is made larger round than the high¬ 
est point on any cam so that the whole shaft with its 
cams may be put in place endwise through the bear- 

* 35 










Section 1 

36 


MOTOR CAR PARTS 


ings. In older types the cams are separate pieces 
fastened to the shaft with taper pins or keys. 

A cam mounted on a shaft and having a rod or wheel 
or roller resting on it will move the rod, wheel or roller 
every time the cam turns, the amount of movement 
being controlled by the shape of the cam. 

Cams are mounted on a cam shaft and are used to 
open the valves of a poppet valve engine. 

A. Cams are fastened to the shaft in such a position 
that they open the valves and allow them to close at 
just the right time. This work is done at the engine 
factory and cannot be altered in the repair shop. The 
valve timing is changed by moving the timing gears. 

T. A cam loose on the shaft causes a loud knock¬ 
ing noise. New keys or key ways or both must be 
made and fitted or the pin holes must be reamed to 
a larger size and new pins driven in tight. 

Should the surface of the cam become worn or 
rough or flat in places the wear will continue rapidly 
until it produces loss of engine power and possibly 
noise. It is then necessary to have new cams and 
probably new parts against which the cams work. 

Cam Shaft. D. The cam shaft is mounted in bear¬ 
ings carried by the crank case in the upper part and 
is made to turn once for every two revolutions of 
the crank shaft by the timing gears. 

A. The cam shaft is usually carried in plain bronze, 
brass or babbitt bearings but may be carried by an¬ 
nular ball or roller bearings. Looseness of these bear¬ 
ings' causes a loud pounding noise. The cam shaft 
must be removed to adjust them. 

To remove the cam shaft and bearings— 

1st—Take off or release all valve springs. 


MOTOR CAR PARTS 


Section 1 

37 


2d—Bronze, brass, annular or roller bearings are 
held from endwise movement by set screws or bolts 
passing through the crank case from the outside and 
holding the bearing or bearing housing in place. 
These screws or bolts must all be located and re¬ 
moved. Annular or roller bearings are sometimes 
held by covers or holders that screw or bolt to the 
crank case at the ends of the cam shaft. Bearings 
may also be held by collars threaded into the case at 
each side of the bearing. Sometimes all the bear¬ 
ings come out on the shaft, in other cases one or 
all the bearings remain in the case. 

In cheap constructions the cam shaft may be held 
in babbitt bearings which are poured around the shaft 
while it is in place. These bearings must be melted 
out with a gasoline or acetylene torch to remove the 
shaft or replace or adjust the bearings. 

3rd—To adjust the bearings see the instructions 
under Bearings. 

If the cam shaft bearings are out of line, that is, if 
their centers are not in the same straight line, the 
bearings will quickly work loose, causing a knocking 
noise. Cam shaft bearings must be placed so that 
they hold the shaft without looseness, yet so that it 
may be turned by hand with the timing gear. 

A bent cam shaft will cause rapid wear on the bear¬ 
ings and knocking and irregular engine operation. It 
may be tested by removing and placing between lathe 
centers. To straighten a cam shaft requires experi¬ 
ence and suitable machinery. 


CARBURETOR. 


D. A carburetor is a device that turns the liquid 
gasoline into a gas or vapor and then mixes this 
vapor with enough air to make a suitable mixture 
for burning in the cylinder of the gasoline engine. 



MILLER CARBURETOR 

This instrument credits its popularity to automobile racing, where it has 
created some enviable records. Its peculiarly constructed pot permits 
unusually rapid acceleration and even gas distribution at varying speeds. 


Every form of carburetor now in use has certain 
parts which are described below— 

Nozzle, a small pipe, or a pipe having a small 
opening, which brings the liquid gasoline into the car¬ 
buretor and from the end of which the liquid comes 
in a fine stream as it turns to vapor and mixes with air. 

38 










MOTOR CAR PARTS 


Section 1 

39 

Mixing Chamber, the tube which surrounds the 
nozzle and carries a stream of air past the opening of 
the nozzle. This air rushes past the nozzle so fast 
that the gasoline is drawn from the end of the nozzle 
in a fine spray. One end of the mixing chamber opens 
to the outside air and is called the primary air in¬ 
take, the other end of the mixing chamber leads to 
the inlet pipe which goes to the cylinders through 
the inlet valves. 

Auxiliary Air Intake. After the gasoline vapor is 
mixed with the air that comes through the primary 
air intake there will not be enough air in the mixture 
for high speeds. More air is allowed to enter the 
mixture above the nozzle through a valve called the 
auxiliary air valve. Between the gasoline tank and 
the nozzle the liquid gasoline passes through a com¬ 
partment of the carburetor called the float chamber. 
Inside the float chamber is a piece of cork or a hollow 
metal piece and as the gasoline comes from the tank 
and rises in the float chamber this float is carried 
higher and higher. To the float is attached a lever 
and this lever operates a valve in the pipe coming from 
the tank. When the float reaches a certain height the 
float valve closes and prevents any more gasoline from 
entering the carburetor. When the gasoline is high 
enough in the float chamber to close the float valve the 
liquid has risen in the nozzle to a point 1/16 to 1/8 inch 
below the nozzle opening. This point is called the float 
level of that carburetor. Between the carburetor and 
inlet valves of the engine is a valve controlled by the 
driver for admitting more or less of the mixture to 
the engine, this valve being called the throttle valve. 


Section 1 

40 


MOTOR CAR PARTS 


Some carburetors are made with the float chamber 
in the form of a ring around the mixing chamber and 
nozzle. The float is then in the shape of a horse shoe 
or hollow ring. This is called a concentric float and 
this type of carburetor may be mounted in any posi¬ 
tion or turned any direction inasmuch as the level 
of the gasoline at the nozzle is always maintained 
at the same point by the float surrounding the 
nozzle. 

The float chamber may be located at one side of 
the mixing chamber, in which case the float cham¬ 
ber should be toward the front of the car so that the 
gasoline will remain in the nozzle while going up 
hill and will lower only when going down hill. This 
precaution is not really essential in well designed 
modern carburetors but was observed in many cases. 

C. The float chamber and nozzle of the carburetor 
should be kept clean and free of grit or foreign mat¬ 
ter as anything passing up into the nozzle opening 
will stop the flow of gasoline. 

All joints in and around the carburetor and the 
piping carrying the liquid gasoline and the mixture 
after it leaves the carburetor should be made perfectly 
air and gas tight and should be kept this way at all 
times. 

A. Carburetors are adjusted to make a suitable mix¬ 
ture under varying conditions by changing the amount 
of gasoline or air or of both gasoline and air admitted 
to the mixing chamber. 

The flow of gasoline is changed by a needle valve 
screwed into or out of the nozzle opening so that 
more or less liquid is allowed to pass by changing 


MOTOR CAR PARTS 


Section 1 

41 


the size of opening. This needle valve may be ad¬ 
justed by hand or by being connected to the air valve, 
throttle valve or other moving part. 

The amount of air admitted to the primary air in¬ 
take is not adjustable in most types, although car¬ 
buretors are made having means for changing the size 
of the primary opening. The auxiliary air valve is 
regulated by nuts or screws which change the tension 
of the spring attached to the air valve. The air valve 
is usually adjusted by hand, but in some cases the 
opening of the air valve is controlled by automatic 
connection to other parts of the carburetor. The 
amount of air may be controlled by the weight of steel 
balls which cover holes in the carburetor wall, by flat 
springs covering similar holes or by any means for 
gradually increasing the opening as the speed and 
suction of the engine increases. 

There may be one or more spray nozzles; when 
there is more than one nozzle the carburetor is said 
to be a multiple-jet type. In the majority of car¬ 
buretors of this type only one, or possibly none of the 
nozzles are adjustable. One of the nozzles is usually 
used for low engine speeds and others for higher 
speeds. In case more than one nozzle is adjustable 
one adjustment would be for low speed, another for 
high speeds, another might be for intermediate speeds. 
There is always some automatic means for bringing 
the proper nozzles into action, such as an increased 
throttle opening uncovering more nozzles, a valve 
that opens over a second or third nozzle as the suction 
increases or any method that will produce substan¬ 
tially the same result. 

There may be only one auxiliary air valve or there 


Section 1 

42 


MOTOR CAR PARTS 


may be more than one. Each air valve is usually 
adjustable separately from the others, one being for 
low speeds, one for intermediate, one for high, etc. 

Standard types of carburetors having a gasoline 
needle valve and a spring controlled auxiliary air 
valve are adjusted in practically the same way re¬ 
gardless of the make. 

If the carburetor has been taken apart o'r if you 
have reason to think that it is badly out of adjust¬ 
ment, see that the level of the gasoline in the nozzle, 
is about one-sixteenth of an inch below the opening. 
This must be tested by looking at the end of the nozzle 
with the carburetor sufficiently disassembled to per¬ 
mit this, yet in such condition that gasoline may be 
admitted through the regular inlet pipe and through 
the float valve, allowing the float and float valve to 
shut ofl the flow at the correct time. This may neces¬ 
sitate removing the carburetor from the car and plac¬ 
ing it on the work bench, admitting gasoline through 
a rubber tube slipped over the end of the gasoline 
inlet pipe. The other end of this tube may be slipped 
■over the lower end of a small funnel held at some dis¬ 
tance above the carburetor while making the test. 

Close the needle valve reasonably tight so that it 
seats, but do not damage the valve or seat by excess¬ 
ive force. Then open the .needle valve from three- 
quarters to one and one-quarter full turns. 

See that the tension on the auxiliary air valve spring 
is just enough to hold the valve firmly on its seat. 

Retard the spark lever, if there is one, and open the 
throttle about one quarter. Turn on the switch and 
start the engine. 

Slowly close the throttle until the engine seems 


Section 1 

MOTOR CAR PARTS 4a 

about ready to stop. Then open or close the needle 
valve until the engine runs faster again without chang¬ 
ing the throttle opening. Close the throttle a little 
more and keep turning the needle valve one way or 
the other until the engine runs as slow as it will run 
without stopping and with the throttle as far closed 
as possible. 

Set the throttle stop screws and the carburetor is 
adjusted for low speed ready for the road test. 

To adjust high speed advance the spark lever, if 
there is one, about two-thirds of the way and open the 
throttle wide for a second or two to see if the engine 
speeds up. Do not keep the throttle open and allow 
the engine to run fast, or “race,” but for a few seconds. 
—just long enough to notice the action. If there is 
no spitting noise from the carburetor, open the air 
valve more and more until there is this noise when 
the throttle is suddenly opened, then close the air 
valve by increasing the spring tension just enough to 
prevent this spitting. Lock the air valve in this posi¬ 
tion if there are means provided for locking. 

Too rich a mixture causes the following (too rich 
means either too much gasoline or too little air in 
the mixture)— 

1. Galloping—one explosion missed every second 
cycle of operations. 

2 . Flooding after the engine stops. 

3. Strong smell from the exhaust. 

4. Overheating. 

5. Loss of power. 

6. Black smoke from the exhaust. 

7. Red exhaust flame when the exhaust manifold is 
removed. 


Section 1 

44 


MOTOR CAR PARTS 


Too thin a mixture causes the following (too thin 
means either too little gasoline or too much air in the 
mixture)— 

1. Spitting noise from the carburetor. 

2. Popping noise. 

3. Hard starting. 

4. Missing explosions. 

5. Loss of power. 

6. Yellow exhaust flame when the exhaust mani¬ 
fold is removed. 

The correct mixture has none of the above symp¬ 
toms and gives a purple exhaust flame when the ex¬ 
haust manifold is removed from the engine. 

To correct a thin mixture open the needle valve more 
if the trouble is at low engine speeds, close the air 
valve more if the trouble comes only at high engine 
speeds or raise the float level if the trouble occurs 
at all speeds. Raising the float level makes the gaso¬ 
line stand higher in the nozzle and is accomplished 
by holding the float valve end of the float lever sta¬ 
tionary while the float end of the lever is raised. Some 
carburetors have screw'adjustments on the float valve, 
or on the spring that resists movement of the float 
valve. 

To correct a rich mixture close the needle valve 
more if the trouble is at low engine speeds, open the 
air valve more if the trouble comes only at high speeds 
or lower the float level if the trouble comes at all en¬ 
gine speeds. Lowering the float level lowers the 
height of the gasoline in the nozzle and is done by 
bending the float end of the float valve lever down. 

There are three ways of overcoming hard starting— 

1. Prime the cylinders by placing about a teaspoon- 


MOTOR CAR PARTS 


Section 1 

45 

ful of liquid gasoline in two or more of the cylinders 
through the pet cocks, or by taking out the spark 
plugs. 

2. Choke the carburetor by shutting off almost all 
the air coming through the primary and auxiliary air 
intakes, thus causing a stronger suction and drawing 
more gasoline into the mixture. This may be done 
by closing small shutters or valves in the air intakes, 
by holding the air valve on its seat by levers or stops 
provided for this purpose, or by placing the hand or 
handkerchief over the air intakes. 

3. Flood the carburetor by pressing the small lever 
or pin on top of the float chamber. This pin passes 
through the wall of the chamber, striking the top of 
the float and holding it down. This opens the float 
valve and admits enough gasoline to the nozzle so 
that a rich mixture is^ produced. 

Breeze Carburetor Adjustment. On top of the 
Breeze carburetor is a round screw head having num¬ 
bers around the edge and held in place by a wire that 
catches in notches around the outside of the screw 
head. This is the needle valve and is used for adjust¬ 
ing for low engine speeds. At the end of the car¬ 
buretor and on top is a wing nut that adjusts the ten¬ 
sion of the auxiliary air valve spring and this is used 
for high speeds. 

First see that gasoline is in the float chamber by 
pressing on the small button or lever found on top of 
the float chamber. This is called a primer, or tickler, 
and when pressed it holds the float down until the 
gasoline rises in the chamber and nozzle high enough 
to overflow the nozzle and drip out below. 

Now screw down on the needle valve by turning 


Section 1 

46 MOTOR CAR PARTS 

it to the right until it turns no farther, thus closing 
the nozzle opening completely. Now open the needle 
valve by screwing the other way three quarters of a 
full turn. 

Next loosen the lock nut on the air valve and screw 
the valve stem up or to the left until the air valve 
comes up against the seat. This can be tested by 
poking the air valve with a pencil through the cage 
that holds it. 

Now start the engine, retard the spark and turn 
the needle valve up or down until the engine runs 
fastest with the spark retarded and the throttle closed 
as far as possible without stopping the engine. This 
adjusts low speed. 

Next advance the spark two-thirds of the way and 
quickly open the throttle and close it. If the engine 
increased its speed with the throttle opening but did 
not miss explosions and did not make a spitting noise 
through the carburetor, screw the air valve stem down 
more, allowing the valve to leave its seat easier. 
Quickly open and close the throttle again and keep 
opening the air valve this way until the engine makes 
a spitting noise through the carburetor. Then bring 
the air valve back about a quarter turn to prevent the 
spitting. 

If the spitting occurred the first time the throttle 
was opened screw the air valve stem farther up or to 
the left, increasing the spring tension and making it 
harder for the air valve to' leave its seat. The car¬ 
buretor is now adjusted, ready to take on the road for 
a test. 

When on the road you can repeat the same tests 


MOTOR CAR PARTS 


Section 1 

47 



HOLLEY CARBURETOR USED ON FORD AND OTHER LIGHT CARS. 

Showing needle valve adjustment on top. 

and readjust the carburetor if the action, speed or 
power of the engine is improved by doing so. 

Holley Carburetor Adjustment. The Holley car¬ 
buretors are made with an adjustable needle valve, but 
there is no adjustment for either the primary or 
auxiliary air intakes. It is therefore necessary to ad¬ 
just the needle valve only. The needle valve is on top 
of the old style Holley carburetors and on the bottom 
of the new Holley. It is adjusted in exactly the same 
way as given in the second, third and fifth paragraphs 
under Breeze Carburetor Adjustment. If there is a 
spitting noise when the throttle is quickly opened and 
closed the needle valve must be opened a little more. 

Kingston Carburetor Adjustment. The Kingston 
carburetor has a needle valve on top of the carburetor 
for adjusting the gasoline, the auxiliary air is ad¬ 
justed by five steel balls that close five holes. These 
balls are underneath the five small nuts seen around 
the top edge of the carburetor and they are not ad¬ 
justable in any way. The Kingston carburetor is ad- 


,Section 1 

48 


MOTOR CAR PARTS 



HOLLEY MODEL “H” CARBURETOR. 

justed in exactly the same way as directed in para¬ 
graphs 2, 3 and 5 under Breeze Carburetor Adjustment. 
Should the spitting noise occur when the throttle is 
suddenly opened it will be necessary to open the 
needle valve a little more. 



KINGSTON KEROSENE CARBURETOR 

Showing two float chambers, one for gasoline, one for kerosene. The 
engine is started on gasoline and when warm the other 
fuel is turned in. 



MOTOR CAR PARTS 



KINGSTON CARBURETOR. 

Showing the method of controlling the auxiliary air supply by means of 
steel balls for valves. 

Rayfield Carburetor Adjustment. The model num¬ 
ber of the Rayfield carburetor is on the outside of the 
part between the mixing chamber and the float cham¬ 
ber, on the side of the carburetor and just above the 
drain cock. Model D has two adjusting screws, both 
of which control the needle valve opening, and an 
auxiliary valve controlled by turning a corrugated 
sleeve which surrounds the air valve. One of the 
screws for controlling the needle valve is located so 
it screws against a piece of metal on one end of the 
throttle shaft, the screw being quite high on the car¬ 
buretor. This screw adjusts high speeds and is the 
smaller of the two. 

The low speed adjusting screw is below the other 
one and points the other way, bearing against a cam 






Section 1 

50 MOTOR CAR PARTS 





/ 


% 




INTERIOR OF THE MODEL G RAYFIELD CARBURETOR. 

































MOTOR CAR PARTS 


Section 1 

51 


at the bottom of a short shaft at the outside of the 
carburetor. 

First see that there is gasoline in the float cham¬ 
ber, then see that the plunger on the driver’s side of 
the dash is pushed all the way in. This plunger con¬ 
nects to a wire that moves an arm on the carburetor. 
The plunger is pulled up or out for easy starting. 

Now unscrew or turn to the left the low speed ad¬ 
justment until the end of the arm just leaves contact 
with the cam under the high speed screw. Then turn 
back to the right one and one-half turns. Open the 
throttle a little ways, retard the spark and start the 
engine. Gradually close the throttle until the motor 
is running as slow as it will without stopping. Then 
turn the low speed screw to the left one notch at a 
time until the motor runs slowly and smoothly. This 
makes the low speed adjustment. 

Next advance the spark two-thirds of the way and 
open the throttle wide and close it quickly. If there 
is a spitting noise from the carburetor turn the high 
speed screw to the right or screw it in one notch at a 
time until when you open the throttle there is no spit¬ 
ting. If the spitting does not occur turn the high 
speed screw to the left until it does spit, then turn it 
back to the right just far enough to prevent spitting. 
This makes the high speed adjustment. 

If the action is not satisfactory at intermediate 
speeds between high and low, change the tension of 
the air valve spring by turning the sleeve a few notches 
to the right or left. 

Models A, B, C, D, E, H, AA, BB, CC, EE, DA— 
Adjust in the same way as the Model D is adjusted. 

Models G and L—Are adjusted in the same way as 


Section 1 

52 


MOTOR CAR PARTS 



THE DAVE 
BUICK 

CARBURETOR 

One of the latest suc¬ 
cessful instruments de¬ 
signed for simplicity and 
positive action during 
rapid acceleration. 



HOLLEY KEROSENE 
CARBURETOR 


Designed to use kero¬ 
sene, benzol, gaso¬ 
line, or any hydro¬ 
carbon with a final 
boiling point below 
600 degrees Fahren¬ 
heit. 






MOTOR CAR PARTS 


Section 1 

53 


the Model D but there is no air valve adjustment to be 
made for intermediate speeds. 

Schebler Carburetor Adjustment. The new Schebler 
plain tube carburetor model “A” is a non-moving part 
carburetor. Several new features and principles of car- 
buretion are incorporated in this instrument. 



SCHEBLER MODEL A CARBURETOR 
The Ford Model is shown 


The pitot tube principle is introduced, which consti¬ 
tutes an improved type of gasoline nozzle so designed 
and built that it automatically furnishes a rich mixture 
for acceleration and thins out this mixture after the 
normal motor speed has been reached. This is said to 
furnish a very economical running mixture at all motor 
speeds, together with a smooth and positive accelera¬ 
tion. 

The first view shown of this model is the type suited 
for use in Ford cars. By studying the section illustra¬ 
tion and its captions you will note that two gasoline 








MOTOR CAR PARTS 


Section 1 

54 

adjustments are furnished. One of these adjustments 
is for low-speed idling and the other for high-speed. 

A double choker is also furnished, so that in the cold¬ 
est weather all necessary adjustments for easy starting 
may be made from the seat. 

To start the motor, open low-speed needle H and 



SECTIONAL VIEW OF SCHEBLER MODEL A CARBURETOR 


high-speed needle I about four or five complete turns. 
You will note that the needles have dials which indicate 
that turning the needle to the right cuts down the gaso¬ 
line supply. Pull out the steering post control, open 
the throttle about one-quarter of the way, retard the 
spark, and pull out the radiator choke wire, which will 
close the shutter in the carburetor air intake. Then 
crank the motor. 

After the motor is started, immediately release the 














































MOTOR CAR PARTS 


Section 1 

55 



radiator choke wire and gradually push in the steering 
post control or plunger, and let the motor run until it 
is warmed up. Then, first adjust the high-speed needle 
I until the motor runs evenly and smoothly with re¬ 
tarded spark. Close the throttle part way and adjust 
the idling needle H until the motor runs smoothly at 


low speed. In order to get the desired low-speed run¬ 
ning, use the throttle stop screw L, which will control 
throttle opening and give desired low-speed running. 

Models D and E—These are rarely met with now. 
They are adjusted by turning the needle valve to the 
right as far as it will go, then opening it by turning it 
back about three-quarters of a turn. 


SCHEBLER MODEL A CARBURETOR 
The layout as shown is for use on Ford cars. 




Section 1 

56 


MOTOR CAR PARTS 


Next see that the air valve is seated, open the throt¬ 
tle about a quarter of the way, retard the spark and 
start the engine. Turn the needle valve one way or the 
other until the motor runs as slowly as possible without 
stopping. 

Next advance the spark two-thirds of the way and 
quickly open the throttle and close it. Adjust back and 


•r 

«• 


SCHEBLER MODEL L CARBURETOR. 

Showing primary air intake through curved tube into bottom, needle 
valve for low speed adjustment and - pointers and dials for intermediate 
and high speed gasoline adjustment. At the left side is the auxiliary air 
valve with small lever for increasing or decreasing the tension of the valve 
spring from the driver’s seat. 

forth on the air-valve screw until the spitting noise 
when opening throttle is eliminated. 

Model L—Has the needle valve just like the Model 
H, and on the part that moves with the throttle are 
two small pointers moving over two dials, ,each dial 
being numbered from one to three. Adjustment is 
made just the same as for the Model H except that the 
right hand pointer and dial is for adjusting the inter¬ 
mediate speeds with the throttle half open and the left 
hand pointer and dial adjusts the high speed. 

Model O—Is adjusted just the same as the Model H, 




Section 1 

MOTOR CAR PARTS 57 

but the small pointer and dial is located on an arm 
that moves with the throttle in place of on top of the 
carburetor. w 

Model R. Has two adjustments, one being a sleeve 
or cage on top of the auxiliary air valve, which is the 
low speed adjustment; the other being a small screw 
head below the auxiliary air valve, which adjusts high 
speeds. The upper adjustment controls the needle 
valve in the nozzle, the lower adjustment controls the 
tension on the air valve spring. 



SCHEBLER MODEL R CARBURETOR. 

Showing primary air intake through curved tube and auxiliary valve 
at the left side. The low speed adjustment is on top of the auxiliary air 
valve and the high speed adjusting screw is seen below the air valve. 


To adjust the carburetor first see that there is gas¬ 
oline in the float chamber, then turn the upper low 
speed adjustment to the right until it stops, then back 
to the left one full turn. Now retard the spark, open 
the throttle a little ways, start the engine and turn 
the upper adjustment to the right or left until the en¬ 
gine runs best with the throttle just as far closed as it 
will go without stopping the engine. This makes the 
low speed adjustment. 



Section 1 

58 


MOTOR CAR PARTS 


Next advance the spark two-thirds of the way and 
open the throttle quickly. If there is a spitting noise 
in the carburetor turn the lower or high speed adjust¬ 
ing screw up or to the right until the spitting just stops. 
If there is no spitting turn the screw down to the left 
or unscrew it until spitting occurs, then turn the screw 
back about one-quarter turn. This makes the high 
speed adjustment. 

New Stromberg Types. All new Stromberg car¬ 
buretors are of the plain tube design, being manufac¬ 
tured in both horizontal and vertical types. The fuel 
after leaving the float chamber passes through a regu¬ 
lating orifice into a gasoline channel, where it is broken 
up by means of air being taken into this channel. This 
mixture then passes around an opening concentric with 
the opening of the venturi and is discharged from a 
number of small jets into the air stream at the throat of 
the venturi. In the construction of the carburetor 
there is a small reserve chamber which fills with gaso¬ 
line when the engine is idling or slowing down, and, 
upon accelerating, this reserve supply of fuel joins from 
the main supply and thus doubles the normal output of 
fuel supply in order to produce a very rich mixture for 
acceleration. The atomizing of the low-speed supply is 
aided directly by dilution of air, which is controlled by 
the low-speed adjustment. 

Thus, by means of two fuel paths it is natural that 
the fuel will follow the one having the greatest suction, 
and by this the highest degree of atomizing is con¬ 
tained. The carburetor is manufactured in five models, 
designated as LB, NB, L, M and Ford. The model L 
has a new atomizer action, whereas the others all oper- 


MOTOR CAR PARTS 


Section 1 

59 


ate on practically the same for the combination and 
priming rings. 

Stromberg Carburetor Adjustment. Stromberg car¬ 
buretors are adjusted by the air valve, this valve being 
mounted or balanced between two springs, one spring 
being for low speeds and the other for high speeds. 
The nozzles for Stromberg carburetors maybe removed 
and replaced by taking out the plug or drain cock at 
the bottom of the mixing chamber, draining the gaso¬ 
line from the carburetor. After this plug is out stick 
a long, thin screwdriver up into this hole until it will go 
no farther. This screwdriver will then be in the slot 
of the small nozzle tip, and by holding the screwdriver 
tight up against the nozzle and turning it to the left 
or unscrewing it the nozzle will unscrew and drop 
down out of the hole. On the sides of these nozzles' 
are numbers 56, 57, etc., up into the sixties. The higher 
the number on the nozzle the smaller the opening in 
the end will be. 

After adjusting a carburetor as directed below if you 
find that the air valve does not touch the seat with the 
engine stopped, then the nozzle is too large and a noz¬ 
zle of the next larger number must be tried. If you 
find that the upper high speed adjusting spring has no 
play and is touching the air valve and nut when the 
engine is stopped the nozzle is too small and one of a 
smaller number should be substituted. 

After selecting the proper nozzle for a car it should 
never be changed. 

Models A, B, and G. See that there is gasoline in the 
glass float chamber, then take hold of the small stiff 
spring on top of the auxiliary air valve and make sure 
that you can move it up and down freely for at least 


Section 1 
60 


MOTOR CAR PARTS 


one thirty-second inch, that is, see that this spring has a 
little play up and down and that it does not touch the 
air valve and the nut on top of the stem at the same 
time. If this spring is tight turn the nut at the bottom 
of the spring down or to the right until there is suffi¬ 
cient play. 

Next turn the small round sleeve on the bottom of 



STROMBERG CARBURETOR 
Special model as used on Dodge cars 


the air valve stem down or unscrew it until the air 
valve drops down from the seat, then screw it up until 
the valve just touches the seat and then up about three 
notches more. 

Now retard the spark and open the throttle a little 
ways and start the engine. Turn the lower sleeve up 
or down a notch at a time until the motor runs as slow 







MOTOR CAR PARTS 


Section 1 
61 

as possible and with the throttle closed just as far as it 
will go without stopping the engine. That is, keep clos¬ 
ing the throttle until the engine is ready to stop, no 
matter which way you turn the low speed adjusting 
sleeve. This is the low speed adjustment. 

Next advance the spark two-thirds of the way and 
quickly open and close the throttle. Should there be a 
spitting noise in the carburetor turn the small nut at 
the bottom of the high speed spring on top of the valve 
up a little at a time until there is no spitting when the 
throttle is suddenly opened. If there is no spitting on 
the first trial screw this small nut down, loosening the 
spring, until there is spitting, then back about one 
notch. This is the high speed adjustment. 

Model C. Is adjusted the same as A and B except 
that the high speed adjusting nut is at the very top of 
the air valve stem. Just under this nut is the end of a 
small lever. When the nut is drawn down by the air 
valve’s opening this lever is pulled down, opening an¬ 
other jet or spray nozzle for high speed. Before adjust¬ 
ing Model C make sure that the high speed nut on the 
top of the valve stem does not touch the small lever by 
at least one thirty-second inch by screwing the nut up 
if necessary. 

In adjusting high speed screw this high speed nut 
down to prevent spitting and screw it up to cause spit¬ 
ting. 

Model D. Is adjusted in the same way as the Model 
C with the exception that the lower or low speed adjust¬ 
ment is made at the factory and should not need chang¬ 
ing. The low speed is not adjusted by a notched sleeve 
but by a screw head with a locking nut. If the air valve 


Section 1 
62 


MOTOR CAR PARTS 


is off its seat with the motor running light at low 
speeds you should turn this low speed adjusting screw 
up until the valve does seat. 

This carburetor has a shutter around the air valve 
that can be opened or closed from the driver’s seat by 
a wire. For ordinary running this shutter should be 
three-quarters of the way open. If the shutter has to 
be closed more than one-half way to go fast, the second 



STROMBERG CARBURETOR—TYPE “C.” 

Showing secondary gasoline jet operated by air valve. 

nozzle, which is operated by the small lever from the 
top of the air valve stem, is too small and a larger one 
is needed. If this shutter has to be fully opened to 
make the motor run smoothly without missing occa¬ 
sional explosions the second jet or nozzle is too large. 

Models H and HA. These types have the air valve 
adjustments above the valve, on the side opposite the 
float chamber. The top adjusting nut handles the high 
speed and the lower adjusting nut (just above the air 











MOTOR CAR PARTS 


Section 1 

63 


valve) is for low speed work. There is a wire running 
to the dash which makes the mixture richer in gasoline 
when it is pulled up or away from the carburetor. 
Turning either adjustment to the right or clockwise or* 
down gives less air or more gasoline; turning either 
adjustment up or to the left gives more air or less gaso¬ 
line in the mixture. 

In starting to adjust these types first set the high 
speed adjusting nut so that there is at least one thirty- 
second inch clearance between it and the brass collar 
below it, with the air valve on its seat. To turn the high 
speed nut it must be first lifted to release the locking 
pin. Also see that the rocker arm moved by the dash 
adjustment does not touch the collar above it. The 
air valve must just touch its seat; this may be accom¬ 
plished by turning the low speed adjusting nut. 

To start the motor pull the dash adjustment all the 
way up and if necessary close the valve in the lower 
air inlet. Let the motor warm up before proceeding 
with the adjustment. 

After the motor starts and runs until warm, adjust 
the low speed nut to give more and more air until the 
engine runs as fast as possible with the throttle closed 
as far as possible. To adjust the high speed, advance 
the spark two-thirds of its travel and open and close 
the throttle quickly. Turn the high speed nut up, 
giving more and more air until there is a spitting noise 
when the throttle is opened and then turn it back far 
enough to prevent this spitting. After completing the 
adjustment there must be clearance between the high 
speed nut and the collar below it. 

Model K. This is a concentric float type with but 


Section 1 

64 MOTOR CAR PARTS 

V 

one adjustment, this being a nut for controlling the 
air valve and placed directly over the air valve. 

To adjust the carburetor turn the nut up to the left 
or anti-clockwise until the air valve leaves its seat 
(when pulling upon the adjusting nut there is a click 
heard if the valve is off its seat). Now turn the ad¬ 
justment the other way until the valve just seats and 
the click disappears, and then turn it two more notches 
in this same direction. Turning this adjustment up 
to the left or anti-clockwise gives less gasoline or 
more air. 

Zenith Carburetor Adjustment. The Zenith car¬ 
buretor has no outside adjustments, and, except in 
unusual cases or from long use, will not need ad¬ 
justment. 

It is a double jet instrument, one jet being in the 
center of the mixing chamber and the other opening 
into the wall of the mixing chamber at a point where 
it is covered when the throttle is completely closed by 
the throttle valve touching and covering the opening 
in the chamber wall. 

The flow of air through the mixing chamber is reg¬ 
ulated by a removable tapered tube that surrounds 
the nozzle and is called the “choke tube.” There are 
no auxiliary air valves or spring controlled valves of 
any kind. 

The nozzle may be changed in size by taking the 
carburetor apart and substituting a new nozzle. In 
the tube between the float chamber and the mix¬ 
ing chamber is a brass tube with a small hole in one 
end called the “well.” Changing this well for one 
having a larger or smaller opening will affect the 


MOTOR CAR PARTS 


Section 1 

65 


adjustment for idling or picking up. Any of these 
changes make it necessary to send to the maker for 
new parts. 

All carburetors have small screws placed some¬ 
where around the throttle, at one side or the other, 
which are for the purpose of allowing the throttle to 
close more when they are unscrewed or for holding 
the throttle wider open by screwing the screws farther 
in. These screws are provided with locking nuts 
or other smaller screws that may be tightened against 
the main adjusting screw. These “throttle stops” 
should be used to make the engine slow down by clos¬ 
ing the throttle more and more, but when a point is 
reached at which further closing of the throttle would 
stop the engine, then the throttle stop screw should 
be set and locked in this position. 

Before deciding that a carburetor needs adjustment 
make sure that none of the following faults are pres¬ 
ent : 

No gasoline in tank or in float chamber. 

Leaks in the inlet manifold or carburetor or cylinder 
flanges. 

Dirt in the nozzle or under the float valve. 

Punctured metal float or gasoline soaked cork float. 

No spark. 

Leaking compression in cylinders. 

No cooling water or not enough oil. 

Water in gasoline and in carburetor. 

R. In reassembling a carburetor notice the follow¬ 
ing things: See that the nozzle is open through into 
the float chamber by blowing through a rubber tube 
slipped over the nozzle. See that the throttle is tight 
on the shaft that works it. See that the air valve is 


MOTOR CAR PARTS 


Section 1 
66 

not binding or sticking and that its spring is not 
broken or bent or flattened. See that the needle 
valve screws in and out so that it can close the nozzle. 
Make sure that a metal float has no holes or gasoline 
in it and that a cork float is dry and does not need a 
new coat of shellac. As the parts are put together 
make sure that every joint is made air and gas and 
gasoline tight either by paper and shellac gaskets, 
copper-asbestos gaskets, or perfectly fitting ground 
joints. 

T. A common trouble that affects the carburetor is 
an air leak in the piping from the mixing chamber to 
the engine. It will be impossible to adjust a car¬ 
buretor with a leak of this kind. See under Inlet 
Manifold. 

If an engine has not good compression the car¬ 
buretor is very hard to adjust and the adjustment will 
not be satisfactory. Test the compression by pouring 
oil around all joints and threads and then turning the 
crank and watching for bubbles. Also look at the 
valves and piston rings for compression. 

TROUBLES THAT MAKE A THIN MIXTURE. 

1. Water in the carburetor. Drain the carburetor. 
Causes the same thing to happen as a thin mixture. 

2. Shut off valve partly or entirely closed. Open. 

3. Piping clogged with dirt. Take the pipe off and 
blow through from the carburetor end of the pipe. 

4. Dirt in the float chamber or in the float valve. 
Take the carburetor apart and clean. 

5. Air leaks around the inlet manifold, spark plugs, 
valve caps or carburetor flange. 

6. Gaskets must be made tight. Test by pouring 


MOTOR CAR PARTS 


Section 1 

67 

oil on the joints and watch to see if it is sucked in out 
of sight. 

7. Broken air valve spring. New spring. If on 
the road, put a plug or wire on the valve to hold it 
closed. 

8. Gasoline tank cap has no hole or vent in gravity 
feed system. Gasoline can’t flow out unless air can 
flow in. 

9. Leaks in gasoline tank or piping with pressure 
feed system. Close up the leaks. 

10. Air valve loose. Should be properly adjusted. 

11. Float sticking. Jar the carburetor to loosen it. 

12. Air valve stem binding. Make a free moving fit 
by filing or use emery. 

13. Piece of something in gasoline tank. Will not 
let the gasoline flow freely when it gets over opening 
to pipe. 

14. Air lock in gasoline pipe. Caused by having the 
pipe turning upward and then downward again, or 
from having the pipe too close to the exhaust piping. 

15. Water lock in gasoline pipe. Caused by having 
the pipe turn downward and then upward again. 

16. Pipe bent or cracked. Should have new pipe 
but may be soldered. 

17. Pressure pump valves not seating. Should be 
thoroughly cleaned or ground in. 

18. Pressure pump screen dirty. Wash with gaso¬ 
line and brush. 

19. Auxiliary dash tank float sticking, punctured or 
soaked. May be jarred loose, dried out and shellaced 
if of cork, or warmed and soldered if metal. 

20. Loose throttle bearings. Must be bushed (in 
old carburetor only). 


Section 1 
68 


MOTOR CAR PARTS 


21. Water gets into mixing chamber. Leaking hot 
water jacket. 

TROUBLES THAT MAKE A RICH MIXTURE. 

1. Float sticking. Carburetor floods. Jar with 
hammer handle. 

2. Dirt under needle or float valve. Carb.uretor 
floods. Jar. (Should be cleaned.) 

3. Fuel level too high. Lower the float level. 

4. Air valve screwed down too tight. Loosen and 
adjust. 

5. Needle valve too far open. Close. 

6. Float valve parts loose. Take apart and tighten. 

7. Shoulder worn on needle valve. Must be dressed 
down with fine file or grind on its seat with powdered 
glass and thin oil. 

8. Cork float gasoline soaked. Dry in warm room, 
then shellac and dry. 

9. Metal float punctured. Drive gasoline out of 
float by placing in a basin of hot water, or as warm a 
place as possible away from a flame. Locate the hole, 
solder and remove all extra solder. 

Every possible carburetor trouble must make the 
mixture either too thin or too rich. First find which 
way the mixture is wrong and then look up the troubles 
in the order given. 

After a gasoline engine is running much more air 
can be added to the mixture. This extra air gives 
more power with less gasoline and keeps the engine 
in better condition for hard and fast work. After 
adding this air, should the engine be stopped it could 
not easily be started again without cutting off the 
extra air supply. To secure the advantages of this 


MOTOR CAR PARTS 


Section 1 

69 


extra air there are many forms of valves, either hand 
operated or spring controlled, and arranged so that 
they add air to the mixture after it leaves the car¬ 
buretor by being attached in the inlet manifold. An 
extra air inlet can be easily attached by boring and 
threading a hole in the inlet manifold above the car¬ 
buretor and before it branches to go to the different 
cylinders. Into this hole screw an ordinary pet cock 
with the longest handle possible to find. Bore a hole 
in this handle and run a rod or stiff wire up to the 
steering column so that the driver can open or close the 
valve while running. Before stopping the engine this 
valve should be closed so that the engine will start 
easily. When the car speed becomes low in regular 
driving this valve should be closed or when the throttle 
is opened the engine will stop. 

Automobile and automobile parts makers have found 
it necessary to make several detailed changes in the 
modern motor assemblies in order to assure easy start¬ 
ing of the motors and complete combustion of the fuels. 
These measures have been made necessary because of 
the constantly diminishing quality of available gasoline. 

The gasoline of today will test about three-quarters 
as efficient as the gasoline of four or five years ago. 
This decrease in efficiency lies in the fact that the pres¬ 
ent-day gasoline is a heavier fuel than the old. 

Here is what happens: In order to burn gasoline in 
the cylinders of a gasoline engine the fuel must have 
oxygen. Oxygen is one of the important elements con¬ 
tained in air. Therefore, in order to furnish the gaso¬ 
line with the necessary amount of oxygen to create 
perfect combustion, a stream of air must be forced into 
the cylinders, in mixture with the gasoline. 


Section 1 

70 MOTOR CAR PARTS 

This mixing of air and gasoline is the function of the 
carburetor. The instrument serves not only as a 
medium for breaking the liquid gasoline into a gaseous 
vapor, but it mixes this vapor with just the right 
amount of air to burn all of the gasoline vapor that is 
injected into the cylinders. 

In order to create this mixture the stream of air is 
caused to pass over or through a spray of gasoline. 
There can not be too much or too little air, nor can 
there be too much or too little gasoline. In other words 
the mixture must be exactly right or there is misfiring 
and imperfect combustion in the cylinder. 

To this must be added the fact that the same mixture 
is not correct for all speeds of the motor. During ac¬ 
celeration, that is, when the throttle is opened and the 
motor is pulling heavily to increase the speed of the 
car, the mixture must be rich in gasoline. At high 
operating speeds the mixture can be comparatively thin 
in gasoline. Therefore the carburetor is also called 
upon to vary the consistency of this mixture of gasoline 
vapor and air. 

When the available gasoline was of higher test—that 
is, when it was lighter—it would vaporize more readily, 
was more volatile. Then it was a more simple matter 
to feed a good mixture rapidly into the cylinders. 

But as gasoline becomes of a heavier grade, less 
volatile, it is harder to pick up. The air jet which is 
drawn violently into the gasoline spray has a harder 
time picking up the necessary amount of gasoline vapor, 
and carrying the vapor with it all the way into the 
cylinders. This is particularly evident during accelera¬ 
tion, at which time there is a heavy jet of air being 
drawn into the cylinders and, as previously stated, a 


Section 1 

MOTOR CAR PARTS 71 

rich mixture of gasoline vapor is needed. The air will 
“slip over” the gasoline, or because of its lightness in 
comparison with the gasoline vapor will beat the vapor 
to the cylinders, with the result that the motor mis¬ 
fires because the cylinders are starved of fuel. 

One means of minimizing this difficulty is in the con¬ 
struction of the carburetors themselves—in the meth¬ 
ods of mixing the air and gasoline and in breaking up 
the gasoline into vapor. But that does not come under 
the head now under discussion. 

Another means of reducing the effects of low-grade 
fuel is to heat the fuel itself before it is drawn into the 
cylinders. This is accomplished in various ways. 

Heated fuel or heated gasoline vapor is more volatile 
than cold fuel or vapor. There is exactly the same 
comparison in this regard as there is between cold 
water and heated water. It takes far less energy to 
convert heated water into vapor, or steam, than it does 
cold water. This matter of heating the gasoline is lim¬ 
ited. The fuel in the carburetor can be heated to such 
an extent that a vapor of fuel is caused to rise con¬ 
stantly from it, therefore making it impossible to obtain 
the proper explosion mixture. Then, of course, in the 
extreme case, if gasoline is made to boil it is quite im¬ 
possible to obtain a correct mixture. Fortunately, in 
the case of utilizing the heat created by the explosions 
of the engine, it is practically impossible to get too 
much heat to the gasoline. The trouble has arisen' 
where attempts were made to apply outside heating 
agencies, such as electricity. 

It is true that by perfection of carburetors, use of hot 
air for the mixture, hot water jacketing of the car¬ 
buretor, etc., the modern low-grade gasoline is quite 


Section 1 

72 


MOTOR CAR PARTS 


satisfactorily vaporized. But the mere vaporizing of 
the fuel in the carburetor is not sufficient to insure the 
right kind of explosion. Probably the greatest diffi¬ 
culty which this poor fuel has created is that of getting 
the vapor into the cylinders in the same state as it 
leaves the carburetor. 

Gasoline, in comparison with water and other heavier 
liquids, is very easy to vaporize. It is also just as easy 
to condense once it has become vaporized. Therefore 
the design of the engine must be such that condensation 
cannot take place in the vapor on its way from car¬ 
buretor to cylinders. 

The first step to eliminate vaporization was the heat¬ 
ing of the inlet manifold. In practically every modern 
engine the inlet manifold is heated in some form or 
other. Usually the practice is to run the inlet manifold 
alongside the exhaust manifold so that the heat from 
the explosions is directed onto the. walls of the inlet 
manifold. In some of the latest engines the inlet mani¬ 
fold is in the center of the cylinder head, completely 
surrounded by hot water. This is a very satisfactory 
design inasmuch as the manifold walls are kept at a 
fairly constant high heat. 

Another step adopted was to reduce to a minimum 
the reach between carburetor and farthest cylinder. 
The long inlet pipes are a thing of the past. The car¬ 
buretor is located directly in the center of the engine 
with a very short reach to the inlet manifold itself. 

Yet another step was the introduction of the so-called 
“hot spot.” This hot spot consists of a thin wall of cast 
iron separating the inlet from the exhaust manifold, 
and it is placed directly opposite the carburetor inlet 
passage. 


Section 1 

MOTOR CAR PARTS 73 

The gasoline vapor is drawn from the carburetor by 
the down stroke of the piston, and is then thrown vio¬ 
lently against this wall of cast iron, which is kept at a 
high state of heat by the exhaust gases. The result of 
this action is that the gasoline vapor is broken up, 
meaning that it is made into a still finer vapor, and is 
heated to a point where it will pass into the cylinders as 
a hot, dry gas ready to explode and burn quickly and 
completely at the first spark from the spark plug. 

Owners of old cars are finding a great deal of diffi¬ 
culty in making their engines fire evenly and also are 
noticing that these old engines have lost their powers 
of rapid acceleration. The reason for this is simply that 
the power plants in those old cars were designed for 
the good grade of fuel that was available when they 
were marketed. To make them operate successfully 
today, either one must buy the expensive high-test 
gasoline, or he must alter his power plant to meet pres¬ 
ent conditions. 

New carburetors can be fitted to these old cars and 
equipped for heating the gasoline. One can buy a car¬ 
buretor fitted with a hollow jacket around the chamber 
something like the water jacket around the cylinders. 
These jackets ordinarily have two openings threaded 
one-eighth or one-fourth inch pipe thread. To provide 
heat from the exhaust it is necessary to drill a hole in 
the exhaust manifold and thread it the same size as the 
holes in the carburetor jacket. With tube fittings con¬ 
nect this exhaust pipe opening to one of Rie openings in 
the carburetor jacket, using copper tubing. 

To the remaining opening in the carburetor jacket 
fit a length of copper tubing to lead the gas outside the 
engine pan, on account of the possibility of sparks from 


Section 1 

74 


MOTOR CAR PARTS 


the exhaust. It is customary to fit a pet cock into the 
exhaust manifold hole and then fasten the tubing to 
this pet cock so that heat can be turned off in very hot 
weather. 

Another way to fix up the old cars is to put on a hot 
water jacket carburetor. Hot water heating gives a 
more even heat than the exhaust gas, but it is harder to 
apply. The same jacket carburetor may be used for 
either method. 

To attach hot water heating, drill and tap a hole into 
any water pipe leading from the cylinders to the top of 
the radiator. Run a copper tube of the largest possible 
size from this opening to the hole in the carburetor 
jacket that is highest up. Next bore and tap a hole in 
the pipe coming from the bottom of the radiator or else 
tap into the lower part of the radiator itself. From this 
opening fun another copper pipe to the hole in the car¬ 
buretor that is lowest down. Place a pet cock in one or 
both of these pipes so that the heat may be turned off 
and so that the carburetor may be removed without 
waiting to drain all the water. 

If the car is so old that it is not equipped with a 
system for heating the air which is drawn into the 
carburetor to mix with the gasoline vapor, then one 
should equip the carburetor this way. Hot air stoves 
and piping, can be procured from any automobile sup¬ 
ply house. The stoves, so-called, are iron castings 
which are clamped .onto the exhaust manifold. To the 
stove is attached tubing which connects with the air 
intake of the carburetor. 

To make the necessary connections, first make or 
buy a sheet metal hood or loose clamp that will draw 
hot air from around the exhaust pipe into a tube or pipe 


MOTOR CAR PARTS 


Section 1 

75 


that leads to the primary air intake of the carburetor. 
Fasten this hood or stove firmly around the exhaust 
pipe, but set away from the surface of the pipe about 
one-half inch and run copper or brass tubing or flexible 
tubing to the lower or primary air intake on the car¬ 
buretor. 

Another important device for combating the hard 



IMPERIAL PRIMER 

A device to inject a spray of gasoline into the cylinders as a priming 
agent for easy starting. 


starting trouble due to the present poor grade of fuel, 
is the dash primer. The Imperial primer, illustrated, 
makes it possible to drive a car immediately after 
starting the motor in very cold weather without wait¬ 
ing for the motor to warm up. It will also start the car 
on one or two turnovers of the motor, regardless of 
how cold the weather. 

The device consists of an assembly including a 
plunger pump on the dash, piping to a primer can 
located under the engine hood, and piping to the intake 
manifold of the motor. 

By drawing out the plunger on the dash a charge of 











MOTOR CAR PARTS 


Section 1 

76 

gasoline is drawn from the priming can into the barrel 
of the pump. Then by pushing the plunger in this 
charge of gasoline is thrown forcefully into the mani¬ 
fold, and when the motor is in motion is drawn into the 
cylinders as a rich spray of gasoline. 

This device is of such a character that it is applicable 
to any make of car and is easily installed. 


CHAINS, DRIVING. 


D. Driving chains are of three forms, roller, silent 
and block. Roller chains are made with pins passing 
from side to side into short pieces of steel, each pin 
forming a hinge so that the chain can turn around the 
sprocket. These pins have a hardened steel,'hollow 
roller around them so that the roller takes the wear of 
the sprocket and allows the turning to come between 
the roller and pin. This type is used for driving the 
car and for almost every other use around the car 
where chain drive is required. 

Silent chains are made of a great many V-shaped 
pieces placed side by side and pinned with a pin pass¬ 
ing through each of them. Two pins pass through the 
upper part of the V, each pin passing through alter¬ 
nate pieces. In use, this type of chain has the property 
of filling the space between the sprocket teeth entirely, 
making the operation quite noiseless. A silent chain 
also compensates for wear to a certain extent. This 
type is used for driving cam shafts, magneto shafts, 
electric lighting dynamos, electric starting motors, etc. 

Block chains are made with solid steel blocks shaped 
to -fit between the teeth of the sprocket and pinned 
together by flat pieces on the outside of the blocks. 
Block chains are very little used at present except for 
the lightest work. 

C. Chains should be kept properly adjusted and 
should be cleaned and oiled every 500 miles when 
they run in the open air. 


77 


Section 1 

78 


MOTOR CAR PARTS 


To clean and oil the chain, first wash it thoroughly 
in kerosene and hang it up until dry. Now prepare a 
mixture of tallow and powdered graphite, heated until 
the graphite can be stirred into the tallow in the pro¬ 
portion of one-half pound of graphite to two pounds of 
tallow. Dip the chain into this hot mixture and keep 
hot until the chain is well soaked with the grease. Lift 
the chain out of the grease and allow the grease to drip 
back into the pan. As the chain cools wipe the excess 
grease off with a cloth. The chain is then ready for 
use. 

Should it be impossible to lubricate as given above 
the chain may be wiped off with a cloth and a special 
grease, bought as chain compound or chain grease, may 
be rubbed on the inside of the chain where it touches 
the sprocket. 

A. There should always be some means of length¬ 
ening the distance between the chain sprockets to take 
up the stretch of the chain due to wear. In adjusting 
chains tighten them by setting the sprockets farther 
apart until the loose side of the chain can be lifted up 
and down about one inch for each eighteen inches be¬ 
tween sprockets. 

When the sprockets have been separated as much 
as possible and the chain is still loose, the chain itself 
may be shortened by removing a link. To do this re¬ 
move one of the short side pieces which may be held 
in place by cotter pins, or by a hole and slot in the 
piece which must be moved endwise of the chain, or 
by being riveted. The link that comes apart on a chain 
is usually marked by having the side piece of a special, 
or different shape from the others. After taking off the 
side piece the pins may be drawn out from the other 


MOTOR CAR PARTS 


Section 1 

. 79 


side, carrying the opposite side piece with them. The 
loose ends should then be hooked back together and 
fastened as before. 

Removing one link shortens the chain twice the dis¬ 
tance between two sprocket teeth. If this is too much 
change a “half link” may be bought. This is made with 
one end to go over the outside of one of the rollers, the 
other end going inside the side pieces. This form of 
link shortens the chain the distance between one tooth 
and the next one. 

R. In placing a chain on its sprockets it is easiest 
if the chain is passed over each of the sprockets, leav¬ 
ing the loose ends on top. By turning one of the 
sprockets while the other one is stationary the ends of 
the chain may be brought near enough to fasten. 

Always place a chain so that the removable link or 
side of the links is on the outside where it may be 
easily reached. 

T. Should one chain break on a double chain drive 
car you can proceed with one chain by fastening the 
other driving sprocket so that it cannot turn. This may 
be done with part of the old chain or wire or rope. 
The car will then run- twice as fast on the remaining 
chain due to the action of the differential. 

To detect a worn chain remove it from the sprockets 
and try to bend it sidewise. It should not bend much 
more than % of an inch to the foot of length. The 
only remedy for worn chains is new ones. 

A worn sprocket that has the teeth cup shaped on 
the driving side may be reversed or turned around so 
that the other side of the teeth will wear. This may 
be done by placing the left hand sprocket on the right 
hand side if in no other way. 


Section 1 
80 


MOTOR CAR PARTS 


In ordering roller chains or repairs three dimensions 
must be given in addition to the length or number of 
teeth wanted. The “pitch” of a chain is the distance 
from the center of one roller to the center of the next 
one to it. 

The “diameter” is the outside diameter of the roller. 

The “width” is the width of the roller, which is the 
same as the thickness of the sprocket it runs on. 


CLUTCH. 


D. Clutches are placed between the engine and the 
change speed gearing of the transmission so that the 
power of the running engine may be gradually applied 
to turn the wheels. 

Four types of clutches are in common use. The cone 
clutch is a wheel with the rim at a slant and covered 
with leather or asbestos. This rim is fastened to the 
transmission and fits into the flywheel, which is turned 
out tapered to receive the clutch. The clutch is held 
into the flywheel by a spring or springs and may be 
withdrawn by a foot pedal and levers. 

A multiple disc clutch is formed of a large number 
of metal discs, alternate discs being fastened to the 
engine flywheel and to the transmission shaft. Press¬ 
ing these discs together with a spring causes the engine 
to drive the car and separating them with a foot pedal 
and levers releases the drive. These discs are made 
from steel, iron or bronze and may be faced with asbes¬ 
tos, leather or cork. The clutch runs in oil. 

The dry-plate clutch could probably be termed the 
most recent development in clutch design, and within 
the last two years it has been meeting with ever-in- 
creasing favor; in fact, a majority of present-day cars 
have adopted it. 

The reason for the popularity of the dry-plate clutch 
is that it is positive and smooth in action, is very simple 
in construction and number of parts and requires but 
little attention. 


81 


MOTOR CAR PARTS 


Section 1 

82 

Its form of operating is similar to that of the multiple 
disk, except that instead of having a great number of 
disks it has, in the most common form, but three. It 
differs from the multiple-disk oil type in that it is a 
dry clutch, running in the open air, and has a consider¬ 
ably greater clutching diameter. 

The dry-plate clutch has as its front plate the surface 
of the flywheel itself. Behind this is a free plate, faced 
with non-burnable fabric, and behind this is the clutch¬ 
ing plate itself. This clutching plate is actuated back 
and forth by a series of levers which are so designed 
as to exert a strong leverage action with a very short 
thrust. In other words, the leverage ratio between the 
clutch pedal is such that the clutch pedal is thrown a 
considerable distance while the clutching surfaces 
change but slightly. 

Thus, this type of clutch is of very smooth action. 
Because of the large friction surface which is presented 
by the disks there is but little wear. 

Operating against the collar which actuates the 
levers is a strong coil spring. When the clutch pedal is 
let down this spring serves to keep the clutching sur¬ 
faces in contact, thus making a positive drive from the 
engine to the rear axle. The spring does not need to 
be of the weight used in other types of clutches, mean¬ 
ing that the resistance to be overcome by foot pressure 
is less, with the result that the action is very easy. 

A band clutch operates on the same principle as a 
brake, the drum being fastened to the engine and the 
outside band or inside shoes being fastened to the trans¬ 
mission. This type is very little used. 

R. Clutches are usually more or less difficult to re¬ 
move from the car. If the clutch is in the same case 


MOTOR CAR PARTS 


Section 1 

83 


with the engine and transmission, called a unit power 
plant, it can only be removed by taking the universal 
joint apart back of the clutch* Then take out all the 
bolts that hold the transmission case to the engine 
case, remove the transmission and then take the clutch 
off the front end of the transmission. Unless the 
operating levers and pedals are all carried on the trans¬ 
mission case, all connections must be removed so that 
the transmission is free from all other parts. 

If the clutch is in the same case with the transmis¬ 
sion but separate from the engine it may be removed 
by uncovering the case and taking off the bearing caps 



CROSS SHAFT AND ARMS FOR RELEASING CLUTCH. 


at each end of the clutch and disassembling the uni- 
versals or joints at each end. The clutch should then 
lift out of the case if all operating levers and parts have 
been detached. 

If the clutch is fastened into the flywheel and sep¬ 
arate from the transmission it will first be necessary to 
disconnect the universal joint between the clutch and 
transmission. Then remove all the clutch operating 
parts and parts that connect it to the car, engine or 
transmission. 

If it is a cone clutch you will find one or more rather 
large nuts at the rear end directly in line with the end 
of the crank shaft. These nuts or bolts are locked in 
7 




MOTOR CAR PARTS 


Section 1 

84 

place with special washers, locking nuts, pins, or by 
having a smaller bolt in the center of the large one. 
Removing or loosening these nuts or bolts will allow 
the clutch to be drawn off the end of the crank shaft. 

In some cases the holding bolts will be found in the 
arms of the clutch wheel or spider, in which case there 



CLUTCH AND BRAKE PEDALS. 

Showing method of fastening to the parts to be operated. 


will be a bolt or nut and spring fastened to each arm. 
They must all be loosened or taken off. 

Band, dry plate and disc clutches are usually held in 
place by a number of bolts or pins near or around the 
edge of the clutch inside the flywheel rim. 

Enclosed multiple disc clutches are bolted to the fly¬ 
wheel by three or more bolts around the edge of the 
case. 


MOTOR CAR PARTS 


Section 1 

85 


Band. C. The center bearing on the crankshaft or 
extension should have two or three turns of a grease 
cup each day of use and the thrust release bearing 
should have grease every day. Heavy cup grease is 
best in these parts. 

The surfaces of the drum and shoes or bands must 
be kept clean and dry at all times unless the clutch is 
enclosed and designed to run in a bath of oil. 

A. The adjustment of a band clutch is made by 
means of a screw or nut inside the drum or in the band 
on the drum. Tightening or loosening this adjustment 
will tighen or loosen the clutch. Care should be used 
in this adjustment as a quarter turn will make a great 
difference in the clutch action. Turn the adjusting 
screw a very little and then try the clutch action with 
the engine running. Adjustment may also be made by 
tightening or loosening the clutch operating spring 
which may be in the clutch or outside and attached to 
some of the operating parts. 

T. Band clutches will give trouble of various kinds. 
They may drag or spin (refuse to stop quickly when re¬ 
leased by the pedal), grab (take hold too quick), or 
slip while the engine is pulling the car. 

Some band clutches have the parts all metal. If the 
contact surfaces become rough they must be turned in 
the lathe until smooth and true. 

If the shoes or bands have a separate facing it is re¬ 
newed as described under Brakes. 

If the clutch drags or spins the main bearing may 
be excessively worn so that it needs replacement or 
this bearing may only need oiling. Too tight an ad¬ 
justment will also cause the clutch to spin. 

If the clutch grabs, the contact surfaces may be dirty 


Section 1 


MOTOR CAR PARTS 


86 


and need to be cleaned but not oiled, or the adjustment 
may be too tight. The spring tension may be too great 
or play in the operating parts may allow the clutch to 
engage too quickly. 



A slipping clutch probably has oil or grease on the 
surfaces, is not adjusted tight enough or has not enough 




CONE CLUTCH. 

Showing clutch spring with nut on end of shaft for changing its tension. 

spring tension. Slipping is also caused by the bearings 
or moving parts being so worn that the surfaces do not 
make full contact. 

Cone. C. There are two bearings in a cone clutch 
which require constant lubrication. One of them is the 
bearing on the end of the crank shaft or the extension 









































MOTOR CAR PARTS 


Section 1 

87 

in the flywheel on which the center of the clutch turns. 
This bearing has a grease cup which must have two or 
three full turns every day of use. Failure to do this 
may cause the clutch to seize on the shaft so that it 
will not release. The other bearing is the one that is 
used to pull back on the clutch so that it will release 
from the flywheel. This must be greased every day the 
car is used. 

The facing of a cone clutch must be kept clean and 
free from grease or oil on the surface. 

A. Cone clutches are adjusted by tightening or loos¬ 
ening the spring or springs that hold the cone into the 
flywheel, by moving the bolt that is in the end of the 
crankshaft in the center of the clutch or by turning 
the bolts in the arms of the clutch. After adjusting the 
bolt or nut be sure that it is locked in position and never 
try to turn any of the adjustments until you have re¬ 
leased the locks. 

In order that a cone clutch may take hold easily and 
smoothly the surface of the leather or asbestos facing 
is often raised at certain points around the clutch by 
springs placed under the facing. These springs or 
plungers push the facing up in spots and these spots 
touch the flywheel first. This starts the car easily and 
as the clutch is allowed to press tight into the flywheel 
the easy engagement springs are flattened down so that 
thq whole clutch surface holds. These springs are usu¬ 
ally adjustable from the inside of the clutch rim so that 
the clutch may be made to take hold very gently. 

T. The face of the clutch is covered with leather or 
asbestos brake band lining and as the clutch wears 
this lining or facing becomes worn smooth and thin 
and will finally need replacing. 


MOTOR CAR PARTS 


Section 1 

88 

To attach the asbestos, secure pieces about eight or 
ten inches long and as wide as the face of the clutch. 
These may be bent to shape and attached by riveting 
as directed under Brakes. 

Leather facing requires more preparation than as¬ 
bestos. First secure leather of the proper thickness, 
usually about T 3 e to % inch, in pieces from eight to six¬ 
teen inches long and about one to two inches wider 
than the width of the face of the clutch. The longer 
the strips the wider they must be. 

Soak these pieces of leather in water until wet 
through and then apply them to the clutch face. 

To apply the leather, take one of the pieces and lay 
it over the clutch face so that all parts of the metal 
face are covered with the leather. Lay one end of the 
new piece at the same place that one edge or end of 
the old piece was laid and mark the rivet holes on the 
leather with a punch stuck through the holes in the 
metal face. 

Now countersink the holes as directed under Brakes 
and with the proper size of copper rivets rivet the new 
facing into place, drawing it tightly over the face so 
that the leather covers the metal smoothly. The smooth 
side of the leather should be out so it will touch the 
flywheel. 

Attach each piece in this way until the whole face is 
covered, then allow the leather to dry perfectly and cut 
off the edges that extend over the metal. 

Now soak the clutch over night in neatsfoot or castor 
oil, wipe off the excess oil on the surface and replace the 
clutch in the car. 

If a cone clutch drags or spins it may be that the 
main bearing needs oiling or that this bearing is so 


MOTOR CAR PARTS 


Section 1 

89 


worn that the clutch drops down onto the flywheel rim. 
The clutch spring sometimes sticks in its housing and 
must be freed. The release thrust bearing may need 
oiling or the small shoe or piece that rubs on the clutch 
rim when released may be worn off. This small shoe 
is called a clutch brake and is designed to prevent the 
clutch from spinning when released. The facing on the 
clutch may have pieces sticking up and rubbing on 
the flywheel. 

If this type of clutch grabs, the leather may be dried 
out and you should rub neatsfoot or castor oil onto 
the facing. There may be dirt between the faces or the 
easy engagement springs may not be doing their work 
properly. The main bearing may be so worn that one 
side of the clutch takes hold first and grabs, or the fac¬ 
ing may be worn out and need renewing. 

If the clutch slips while the engine is pulling the car, 
the facing may be too oily or have grease thrown on it. 
It should be washed with gasoline or powdered chalk 
or soapstone should be sprinkled on the leather. The 
clutch facing may be rough or worn out or it may be 
worn so that there is a ridge or shoulder that prevents 
it from going tight into the flywheel. There may not 
be enough spring tension or the operating and release 
parts may be binding so that the clutch can not go tight 
into the flywheel. 

Dry Plate. C. The principal care required by a dry 
plate clutch is that the contact surfaces be kept clean 
and dry and smooth and that the main and release bear¬ 
ings be kept well greased every day. 

Never oil the surfaces of a dry plate clutch. If they 
should become oily or greasy clean them with gasoline 
or kerosene and allow them to dry before using. 


MOTOR CAR PARTS 


Section 1 

90 


A. Dry plate clutches are adjusted by tightening or 
loosening three or more arms or cams or small springs 
found around the arms of the clutch or else by one large 
nut or bolt at the center. Be sure to loosen the locking 
devices before starting adjustment and lock them up 
when finished. 

T. If part of the discs are faced with asbestos or 
leather and this facing is worn out new material may 
be riveted on as directed under Brakes. Use the same 
material and the same thickness as originally used. 



CUT-AWAY VIEW OF BORG & BECK DRY DISK CLUTCH 

If the discs are all metal and have deep ridges worn 
in them they should be replaced with new parts al¬ 
though the ridges may be dressed off by mounting the 
discs on the lathe face plate and grinding with an emery 
wheel on the slide rest. 

If a dry plate clutch does not release properly but 
drags or keeps on spinning, the plates may not leave 
contact with each other because of binding or broken 
parts. The plate surfaces may be dirty or gummy or 
part of the facing may be loose and touching the ad¬ 
joining plates. The main or release bearing may need 
oiling also. 




MOTOR CAR PARTS 


Section 1 

91 


If this type of clutch grabs, there is too much spring 
tension or the surfaces are dirty or gummy. 

If a plate clutch slips the faces may be oily or the 
plates may be worn out or there may not be enough 
spring tension. 

Multiple Disc. C. Multiple disc clutches are lubri¬ 



cated by filling the clutch case or housing not more 
than one-third full of medium weight cylinder oil. A 
heavier oil should be used in summer than in winter. 
Some clutches work best with a mixture of one-fourth 
to one-half kerosene with the oil. 

The release bearing of a multiple disc clutch requires 
oiling or greasing every day if outside the clutch. 

A. Multiple disc clutches are adjusted by increasing 
or decreasing the spring tension by the large nut at the 
back of the shaft or by three or more smaller springs 
around the edge of the clutch. Adjustment may also 
be secured by using thinner or thicker oil or more or 
less kerosene in the oil. 



Section 1 

92 


MOTOR CAR PARTS 


R. In assembling a disc clutch care should be used 
first to find which bolts, keys or pieces revolve with 
the engine and which ones are fastened to the trans¬ 
mission. Every alternate disc should be fastened to 
the engine parts and the other discs to the transmission. 

T. If a multiple disc clutch leaks oil it is usually be¬ 
cause the case is more than one-third full or it may be 
because the felt washer around the shaft at the back end 
of the clutch needs renewing or tightening up. Leakage 
may also come between the clutch case and the flywheel 
where the clutch is bolted to the wheel in which case a 
shellaced paper gasket should be placed at this point. 
The clutch may also leak because the small filling plug 
is not screwed in tight. 

The discs may wear out from long use, lack of oil or 
too much slipping. They will then show deep grooves, 
extreme thinness, warping, bending or discoloration 
due to heat. The only right remedy is new plates. 

Dragging or spinning is caused by too much spring 
tension, by the release parts being so worn that they do 
not give enough movement, or the release parts may 
not be adjusted to give sufficient release. Back of many 
disc clutches is a small disc of steel or steel faced with 
leather against which the revolving part of the clutch 
comes when it is released. This is intended to stop the 
transmission end of the clutch from turning so that the 
gears may be easily meshed and is called the clutch 
brake. If it is worn out or dirty or greasy it will al¬ 
low spinning. The plates may be worn out or warped, 
the oil may be too thick or dirty or there may not be 
enough oil. 

If the clutch grabs there may be too little oil in the 
case, the oil may be old or dirty or too thin. The plates 


MOTOR CAR PARTS 


Section 1 

93 


may be worn or warped, there may be too much spring 
tension or the releasing parts may bind in some posi¬ 
tions. 

A slipping clutch may be caused by the oil being too 
thick, in which case some kerosene should be added. 
The plates may be worn out, there may not be enough 
spring tension or the release parts may not be set to 
allow full engagement or they may bind. 


COMPRESSION. 


After the cylinder of the engine has been filled with 
gas on the inlet stroke, this gas is compressed on the 
following up stroke of the piston with both valves 
closed. It is absolutely essential that but very little, 
if any, of the gas escape from the cylinder during this 
compression stroke. There are many chances for leak¬ 
age and this lost gas causes the engine to lose power 
and to use more gasoline. It also causes missing, hard 
starting and many other troubles. 

* To test the compression of a cylinder—remove the 
spark plugs or open the pet cocks in all the cylinders 
except the one to be tested. Now turn the crank shaft 
with the hand crank until a resistance to turning is felt 
because of the gas being compressed in that cylinder. 
If no resistance is felt all the gas is leaking out. 

To locate the compression stroke turn the crank until 
the exhaust valve opens and just closes. Turn the 
crank one-half revolution from this point of exhaust 
valve closing and you are then at the beginning of the 
compression stroke. During the next half turn of the 
crank the resistance of compression should be felt. 

If the compression is good in the cylinder being 
tested it will be possible to pull the crank part way up 
on the compression stroke and then release the pull 
on the crank. The compressed gas in the cylinder 
should cause the crank to move backward almost to the 
place where you started to pull out. This may be re- 

94 


MOTOR CAR PARTS 


Section 1 

95 


peated a number of times if the compression does not 
leak. The compression should also be good enough to 
make it quite hard to turn the crank around slowly. 
Each cylinder should be tested in this way. 

Leaks of compression may come from around the 



POINTS AT WHICH COMPRESSION MAY BE LOST, 
i, Leaky valve; 2, Leak around spark plug insulation; 3, Leak around 
spark plug threads or gasket; 4, Leak around valve cap; 5, Leak in priming 
cup shut off; 6, Leak around priming cup threads; 7, Poorly fitting piston 
rings. 


threads of the spark plugs, priming cups, valve caps 
or from the joint of a separate cylinder head. Com¬ 
pression may be lost past leaky valve seats or past 
piston rings that do not fit properly. Very rarely com¬ 
pression is lost through cracks in the cylinder or piston 
head. 























MOTOR CAR PARTS 


Section 1 

96 


Leaks around the threads or joints are detected by 
squirting oil around them and then turning the crank 
to test the compression. Bubbles will show the leaks. 
Every joint and gasket should be tried in this way. 
Leaky valves have their face and seat rough or pitted 
and must be ground. The leak past the valve may be 
from dirt or carbon between the face and seat. Leaky 
rings can be detected by looking for blackened or 
browned spots around the ring. They cause a hot 
crank case. 

See under Power, Loss of. 


CONNECTING ROD. 


D. The connecting rod connects the piston to the 
crank shaft and is usually made of an H-section drop 
forging or a tubing. 

T. The connecting rod may be so slightly bent that 
it is not noticeable to the eye and yet this will cause 
trouble in the connecting rod bearings loosening up 
continually. 



EFFECT (EXAGGERATED) ON THE CRANK PIN BEARING OF A 
BENT CONNECTING ROD. 

To test the straightness of a connecting rod, remove 
the cylinder but leave the piston and connecting rod in 
place. Lay one leg of a steel square on the top of the 
part of the crank case to which the cylinders attach or 
to any level and horizontal part of the crank case. Hold 
the other leg of the square straight up by placing a 

97 



















Section 1 

98 


MOTOR CAR PARTS 


smaller square against the side of the first one and bring 
the upright edge of the first square against the side of 
the piston at the point where the wrist pin hole comes 
through. If the piston does not test square to the case 
it must be made so by scraping the bearing or by bend¬ 
ing the connecting rod. 

Forged rods may be bent slightly while cold. 

Few repairmen, even so-called experts, realize the 
extreme care that is necessary in handling the connect¬ 
ing rods of an engine when these are taken out during 
the process of overhauling the engine. It would appear 
that, because of their stockiness and the fact that they 
are made of steel, they would stand a great deal of 
abuse. 

The writer once witnessed a test at one of the large 
engine-manufacturing plants, this test to demonstrate 
the need of care in handling connecting rods. 

A piston, wrist pin and connecting rod assembly 
were dropped onto a concrete floor from a height of 
about three feet. The assembly was dropped so that 
the crankshaft bearing of the connecting rod struck 
the concrete first. Before the test was made, let it be 
understood, this connecting rod showed perfect align¬ 
ment under micrometer tests. It was true in every 
particular. After the drop on the concrete, the microm¬ 
eter test was again applied and it was found that the 
rod was sprung out of alignment twenty-five thousandths 
of an inch, enough to cause the bearings to wear un¬ 
evenly and create distressing results in the power plant 
after it was reassembled. 

Bear in mind that these connecting rods are made the 
lightest weight possible because, the lighter they are, 
the better is the engine balanced. They are designed 


MOTOR CAR PARTS 


Section 1 

99 


to carry a direct thrust right down through the middle 
of the rod, the thrust coming from the explosion. 

If they are dropped, even without the weight of the 
piston, but a very small distance onto some hard object, 
they are going to be sprung out of shape enough to 
cause the trouble which is illustrated on page 97. 

This rule of carefulness holds just as good for the 
crankshaft of the engine. In the same tests referred 
to above, a crankshaft was placed with one end on the 
concrete floor and the other end on the edge of a box 
about 15 inches high. This perfectly aligned crank¬ 
shaft was pushed off of the box and then allowed to 
fall these few inches to the concrete floor. The shaft 
was sufficiently sprung so that the inspectors rejected 
it as unfit for use in an engine. 


COOLING SYSTEM. 


D. The cooling system of a car using water includes 
the water jackets around the cylinders, the piping, the 
radiator and the pump if a pump is used, and a fan. 

C. In order that the cooling system may work prop- 



UPPER ILLUSTRATION—TUBULAR RADIATOR; LOWER ILLUS¬ 
TRATION-CELLULAR RADIATOR. 

erly the cylinder jackets, piping and radiator must be 
kept clean inside and the radiator must be kept clean 
outside. 

The piping must not become bent or filled with 

100 





























Section 1 

MOTOR CAR PARTS 101 

sediment or clogged in any way, the radiator must not 
leak, the pump must revolve so as to force the circula¬ 
tion of the water and the fan bearings must be kept 
adjusted and lubricated and the fan belt and pulleys 
must be clean and tight. 

R. In replacing a pump make sure that all keys and 
pins and shafts are in working order and not sheared or 
broken. Also examine the pump to see that it rotates 
in the direction that will cause it to draw the water 
from the bottom of the radiator and send it to the en¬ 
gine, not the other way around. 

T. To clean the inside of the cooling parts of the car 
first fill the system with water, then draw it off and 
see how many quarts the system holds. 

Make a mixture of caustic soda with water so that 
each eight quarts of the mixture will contain five 
pounds of soda, and make enough mixture to fill the 
system. Caustic soda may be secured from any laundry 
or laundry supply house. It is a strong lye and will 
cause bad burns on the flesh. 

Fill the cooling system with this mixture and run 
the engine ten to twenty minutes. Then stop the en¬ 
gine and drain the mixture out. Wash the system out 
with running water or by filling with clean water sev¬ 
eral times. 

To prevent the water in the cooling system from 
freezing in cold weather many mixtures are used, the 
commonest being alcohol with the water. Mixtures are 
also made from glycerine and water; or half water, 
one-fourth glycerine and one-fourth alcohol. Wood or 
denatured alcohol is usually used. 

One-fifth of wood or denatured alcohol will stand 10° 
above zero, one-fourth alcohol stands 5° above zero 
and one-third alcohol stands 5° below zero. 


MOTOR CAR PARTS 


Section 1 
102 

Wood alcohol lowers the freezing point slightly more 
but evaporates from the mixture faster than denatured 
alcohol. Glycerine damages the rubber in the piping 
slightly. Equal parts of glycerine and alcohol will not 
steam away as quickly if the weather warms up and 
gives the same effect in anti-freezing. Any form of salt 
attacks the metal and any form of oil damages the rub¬ 
ber, causes danger from fire and is dirty and hard to 
circulate. 



INDICATOR FOR TEMPERATURE OF WATER. 

The height of the liquid in the thermometer shows how warm the water 
is. The lowest point shows water ready to freeze, 70° is too cold for effi¬ 
ciency, 130° is the lowest heat for proper operation, 170° is just right and 
above that point the water may boil away. 

Recent developments which serve to maintain the 
correct temperature of the cooling water are thermo¬ 
stats and radiator shutters,, or radiator shields. 

Thermostats are instruments which are placed in the 
water line between the engine and the radiator—the 
line that carries the hot water from the engine. They 
work on the same principle that thermostats do which 
are used for regulating the temperature of a room. 
Until the cooling water has attained a sufficient heat, 
the thermostat holds closed a valve which does not 






MOTOR CAR PARTS 


Section 1 

103 


permit the water to circulate. When the proper heat is 
obtained this valve is opened, allowing the Water to 
pass into the radiator, and thus through the cooling 
system. 

Thus the thermostat opens and closes with the rising 
or dropping of temperature, maintaining the cooling 
water at a very even heat. 



PINE’S RADIATOR SHIELD 

A device for regulating the temperature of the cooling water. 

The radiator shutters are devices which are attached 
to the front of the radiator and are constructed like 
a window blind. They are either hand or thermostati¬ 
cally operated. It is obvious that with the shutter 
closed no air can pass through the radiator; therefore 
the engine heats very quickly. When it is wide open 
there is maximum cooling, and the amount of air ad¬ 
mitted can be varied from minimum to maximum in 
order to obtain the proper cooling effects. 

The Pines automatic radiator shield (illustrated) is 
devised to be attached to the radiator as above de¬ 
scribed. When starting a cold engine the shutters re- 





Section 1 


MOTOR CAR PARTS 


104 


main closed until the water in the radiator reaches a 
temperature of 130 degrees Fahrenheit. As soon as 
the cooling water reaches this temperature the shutter 
remains open to avoid overheating of the engine. 



HARRISON THERMOSTATIC RADIATOR SHUTTER CONTROL 

Troubles in the Cooling System. 

1. Fan belt loose so that fan does not run fast enough. 
Tighten. 

2. Fan bearing sticking. Take apart, clean and oil. 

3. Water level too low. Look for leaking connec¬ 
tions. 

4. Leaks around pump bearings. Put in new pack¬ 
ing (wicking). 

5. Sediment or obstructions in the piping or radiator. 
Clean. 

6. Hose rotted or loose inside. New hose. 

7. Hose kinked. Straighten out or shorten. 

8. Packing or gaskets swollen so that opening is 
closed. Cut the hole out larger. 





Section 1 

MOTOR CAR PARTS 105 

9. Air locks in piping. Comes from having pipes 
turn up and then down again. Straighten them out. 

10. Dirt, oil or scale on the radiator. Clean with 
gasoline or brush. 


Section 1 
106 


MOTOR CAR PARTS 






































CRANK SHAFT. 


R. Crank shafts are carried by either annular ball, 
roller or plain bearings, usually the latter. The crank 
shaft may be fastened into the upper half of the crank 
case (when this half is mounted in the frame) or it 
may be carried in the lower half of the crank case (when 
the lower half is mounted in the frame). 

In the latter case the cylinders and upper half of the 
case must be removed before getting at the crank shaft. 

Other engines have the crank case in one piece, 
called a barrel type, when the crank shaft and its 
bearings are slipped into one end or the other. The 
bearings then are held in large rings that fit into circu¬ 
lar holders inside the case. These rings must be loos¬ 
ened before sliding the crank shaft out. 

T. Should the crank, shaft become ever so slightly 
bent out of line it will cause the bearings to become 
loose continually no matter how often tightened. If 
it is much out of line it will also cause a heavy, dull 
pounding noise. 

The only way to test the trueness of a crank shaft 
is to remove it and place it between the lathe centers, 
turning it and testing each bearing to see if it runs true. 

A bent crank shaft may possibly be straightened un¬ 
der the arbor press while cold if the bend is very 
slight but this is a risky performance. The best way is 
to send it to a large shop or to an experienced man 
having the facilities for this work. 

107 


COUNTERBALANCED CRANKSHAFTS. 


Although counterbalanced crankshafts have been in 
evidence for two years, there is still very little real 
knowledge as to just what counterbalancing means. 

The purpose of crankshaft counterbalancing is to 
eliminate crankshaft distortion, which in turn elim¬ 
inates motor vibration and permits higher operating 
speeds and a greater power output. 

There is the mathematically weighted crankshaft, 
which is really the most satisfactory in every sense of 
the word; the cut-and-try counterbalancing, which is 
built up by experimenting with counterweights until 
the best results are reached, and the crankshaft in run¬ 
ning balance, which does serve to minimize distortion 
and vibration, but does not attain the end that the 
counterweighted crankshaft does. 

Counterweighting combats th'e enormous momentum 
resulting from centrifugal force. A crankshaft must 
revolve, and in order to obtain power it must be re¬ 
volved at a comparatively high speed. Centrifugal 
force becomes evident the minute a crankshaft starts 
to revolve, and the faster it revolves the greater the 
force. 

To explain the action of centrifugal force, if you 
were to tie a brick to a rope and swing it around in a 
circle at arm’s length,the faster you would swing it, the 
greater would be the pull on your shoulder. This pull 
is centrifugal force. This is exactly what occurs in a 
crankshaft. The parts in an engine which represent 
108 


MOTOR CAR PARTS 


Section 1 

109 


the brick in the example above described are the parts 
off center, such as the piston, connecting rods, etc. 
These parts off center are constantly pulling away from 
the rotating axis. 

It is to compensate these forces that the counter¬ 
balanced crankshaft was brought into use. 



DEMONSTRATION OF ACTION OF CENTRIFUGAL FORCE 

Probably the most notable example of crankshaft 
counterbalancing is found in the Hudson Super-Six 
engine. Hudson engineers have computed mathemati¬ 
cally the forces that must be counterbalanced. By 
placing weights at the cheeks of the cranks in such a 
manner as to counteract any tendency to pull away 
from the true center line or axis of rotation, the weights 
naturally keep the center line true; and the faster the 
shaft runs the stiffer it becomes and the truer its axis 
of rotation. 

In any gasoline motor car engine, up to a certain limit 
the power increases with the speed. The greater the 




Section 1 
110 


MOTOR CAR PARTS 


speed of an engine the greater the momentum, and 
therefore the greater the power effort it can deliver. 
The high-speed, small-sized engine of today is much 
more efficient, much more economical than the large 
slow-speed engine of a few years ago. By increasing 
the working speed of the engine the same power has 
been attained with smaller bore and stroke and lighter 



HUDSON COUNTERBALANCED CRANKSHAFT 


working parts all the way through. But this problem 
of combating centrifugal force came up when the speeds 
of engines were increased. 

So-called statically balanced crankshafts were made. 
Such a shaft is balanced so that it has no superfluous 
weight at any point. Suppose you had a grindstone 
which was fastened onto practically frictionless bear¬ 
ings so that the slightest touch would cause it to rotate. 
Naturally the ordinary grindstone would settle so that 
its heaviest side would rotate and finally come to rest 
at the bottom. Another example is the wheel of your 
car. Set it up on a jack, and if the bearings are work¬ 
ing as they should the valve of the tire will finally come 
to rest at the bottom. This is because these objects 
are not in static balance. If it were possible for you to 





MOTOR CAR PARTS 


Section 1 
111 


set the grindstone with its practically frictionless bear¬ 
ings at any position on its rotation, and it would stay 
there without rotating, then the stone would be stati¬ 
cally balanced. 

Tests have been made with statically balanced crank¬ 
shafts. In one test such a crankshaft was spun in a 
crankcase by an electric motor, the pistons and con¬ 
necting rods having been previously removed so that 
the only parts which could exert centrifugal force were 
those off center, such as the crankshaft bearings and 
cheeks. 

The front bearing was taken out in order to observe 
the rigidity of the shaft as it revolved, and it was 
noticed that at 1,500 revolutions per minute the front 
end of the crankshaft became slightly blurred; at 1,900 
revolutions it was distinctly blurred, and at 2,200 revo¬ 
lutions no lines were visible. It was apparently running 
out of true one-sixteenth inch. Above this speed the 
shaft was distorted to such an extent that the lubrica¬ 
tion of the bearings became impossible. 

Upon removing the shaft from the crankcase after 
this test, it was found that it had taken a permanent 
set of one-eighth inch. This bending of this heavy 
crankshaft shows the formidable force which the cen¬ 
trifugal action creates, and it is to offset this action 
and permit the crankshaft to perform perfect rotation 
without distortion at high motor speeds that the coun¬ 
terbalanced crankshaft has been introduced. 


CYLINDER. 


R. In removing cylinder castings from the crank 
case be sure of two things: 

1. That you have removed all wires, pipes, levers, 
manifolds, rods, and everything else that must come 
loose before the cylinders can come off. 

2 . You must prepare to pull the cylinder castings 
straight up and so that you can avoid twisting them 
sidewise, backward or forward. This will prevent 
damage to the pistons or connecting rod bearings. 

The openings in the piston rings must be as far apart 
as possible so that the gas will have to travel a long 
distance sidewise before getting past the rings. If 
there are four rings, the opening in the second one 
should be one-fourth of the distance around the piston 
from the opening in the first one, the third should be 
another quarter of the way around and so on for all the 
rings. 

Before replacing the cylinders the outside of the 
piston and the inside of the cylinder walls must be well 
oiled with cylinder oil. 

Have one piston up and the other down as far as they 
will go and let one man lower the cylinders onto the 
pistons while another holds the pistons straight up and 
in the proper position. The cylinders must be lowered 
into place while being held straight, not twisted to one 
side or the other. 

The man who holds the pistons must press the rings 
112 


Section 1 

MOTOR CAR PARTS 113 

tight into their slots so that the cylinders will slip over 
the rings. This can be done with the thumbs. In some 
cases it will be necessary to squeeze the ring together 
with a metal band or wire. 

The nuts that hold the cylinder to the crank case 
should all be placed on their bolts or studs before any 
of them are made tight. Turn all the nuts down until 
they begin to draw tight and then keep going from one 
nut to the next until all are tightened evenly. Do not 
draw one nut tight and then go to the next. 

T. A cylinder casting may become cracked from ac¬ 
cident or from allowing the cooling water to freeze. A 
cracked cylinder may be repaired by oxy-acetylene 
welding, brazing, cementing, rusting, caulking or patch¬ 
ing. 

Running an engine with too little or no oil or with¬ 
out water causes the pistons to cut scratches or score 
marks on the inside of the cylinder walls. 

If the marks are deep, the remedy is a new cylinder, 
piston and rings; or the old cylinder may be bored 
larger and a larger piston and rings fitted. If a new 
piston is not fitted the looseness may cause a thresh¬ 
ing noise called piston slap. 

If the scratches are slight they may be eradicated by 
lapping. First remove all traces of oil and carbon 
from inside the cylinder and cover the inside of the 
walls with a paste of fine emery powder and cylinder 
oil. Now secure or cut out a piece of iron or steel about 
four inches long and that just slides into the cylinder. 
Fasten a bolt into one end of this piece for a handle. 
The rings may be removed from the piston and the 
piston and connecting rod used in place of the special 
piece if it is impossible to get the piece. 


Section 1 

114 MOTOR CAR PARTS 

Cover the piece of iron or steel or the outside of the 
piston with a coat of the emery and oil and slide the 
piece or piston into the cylinder. Work it back and 
forth and turn it slightly all the time. Continue this 
for some time and then remove the piston or lap, wash 
the inside of the cylinder and see if the marks are gone. 
Repeat this process until the cylinder is smooth. Using 
the piston wears it away faster than it wears the cyl¬ 
inder and causes looseness, therefore a special piece 
should be made if at all possible. 

When the marks are gone fit new rings to the piston 
and after washing every trace of emery from all the 
parts replace them. 

This process is also used for fitting pistons that are 
too tight. 


DIFFERENTIAL. 


D. The differential gearing is for the purpose of al¬ 
lowing one driving wheel to turn faster or slower than 
the other while turning a corner. Both wheels receive 
power from the engine. 



PRINCIPLE OF THE DIFFERENTIAL. 


A. The only adjustment the differential gearing 
could need would be from wear. The worn bushings, 
bearings or gears would have to be replaced with new 
ones. 


9 


115 



























Section 1 
116 


MOTOR CAR PARTS 


Wear in a differential may sometimes be overcome 
by taking it all apart arid reassembling, with the gears, 
bearings, pins, etc., in a different position relative to 
each other. 

R. Before taking a differential apart every gear, pin, 
bushing, bearings, bolt and nut should be carefully 
marked or numbered, showing exactly how they go 
back together in relation to each and all of the other 
parts. Otherwise the differential will be stiff or may 
not turn at all. Mark right and left, up and down, top 
and bottom, front and back. 

When you place the differential with the large bevel 
gear in the rear axle or jack shaft be sure that the bevel 
gear is on the side of the small bevel pinion that will 
cause the wheels to turn forward in the forward speeds 
and backward in reverse. Placing the bevel gear on 
the wrong side will cause the car to have several reverse 
speeds and one forward. 


EIGHT-CYLINDER ENGINES. 


Eight-cylinder engines differ from four and six-cylin¬ 
der types in but four particulars. The differences con¬ 
sist of the increased number of cylinders; the arrange¬ 
ment of the cylinders in two sets of four, set at an 
angle to each other; the changed firing order and the 
construction of the lower end of the connecting rods. 

The increased number of cylinders gives a more even 
and continuous turning effort on the crankshaft and 
presents no greater difficulties to the user or repairman 
than the better known types. 

The cylinders are divided into two sets of four cylin¬ 
ders each, these sets being set at right angles or square 
to each other. This brings one set on the right-hand 
side and the other set on the left-hand side of the car. 
The cylinders have both inlet and exhaust valves on the 
same side, forming what is known as the “L” head type. 
The valves on each set of cylinders are placed on the 
inside or toward the other set of cylinders. This ar¬ 
rangement allows the use of one crankshaft for all cyl¬ 
inders and requires but one camshaft. The camshaft is 
carried on a removable plate directly over the crank¬ 
shaft between the two sets of cylinders. The cylinders 
of one set are placed directly opposite the other set so 
that the whole engine and the crankshaft are no longer 
than a four-cylinder engine and shaft of the same 
cylinder size. 

An eight-cylinder engine may have any one of eight 
firing orders, the one used in any particular engine 

117 


Section 1 
118 


MOTOR CAR PARTS 


being found in the same way that the firing order of 
any other engine is found, that is, by watching the order 
of opening of either the inlet or exhaust valves. The 
cylinders of one set of four may fire in the order 1-3-4-2 
or 1-2-4-3, the cylinders of the other set may fire in 
exactly the same order as the set first considered or 
they may fire in the other order of the two given. The 
cylinder of the second set that fires next after the first 
cylinder in the first set, determines the firing order of 
that engine. 

Indicating the cylinders of the right-hand set by the 
letter R and the cylinders of the left-hand set by the 
letter L, the possible firing orders are as follows: 

1 R-l L-3R-3 L-4R-4L-2R-2 L. 

1R-1L-3R-2L-4R-4L-2R-3L. 

1R-4L-3 R-2 L-4R-1L-2R-3 L. 

1R-4L-3R-3L-4R-1L-2R-2L. 

1R-1L-2R-2L-4R-4L-3R-3L. 

1 R-l L-2R-3 L-4R-4L-3 R-2 L. 

1R-4L-2R-2 L-4R-1L-3R-3 L. 

1R-4L-2R-3L-4R-1L-3R-2L. 

The magneto distributor will have eight terminals 
which must lead to the cylinder ready to fire at the 
time required just the same as in any other engine. 

There are four possible constructions of the lower 
ends of the connecting rods, these being shown in the 
accompanying illustration. 

(1) The two connecting rods of opposite cylinders 
may be placed side by side on the same crank pin, re¬ 
quiring that the cylinders be slightly offset. 

(2) One of the connecting rods may be made of large 
size and with a pair of projecting lugs on one side, these 


MOTOR CAR PARTS 


Section 1 

119 

lugs carrying a pin. The lower end of the other con¬ 
necting rod has its bearing on this pin. 

(3) The lower end of one connecting rod may be 
made in the ordinary way and placed in the center of 
the crank pin. The other connecting rod end is split or 
forked, one leg of the fork being placed each side of the 
first rod end. This gives two bearings in the second 
rod end, each bearing being about half the size of the 
one bearing of the first rod. This method is open to 
the objection that the three bearings on one crank pin 
tend to form ridges or grooves around the pin. 

(4) The rod ends are shaped in the same way as de¬ 
scribed above, that is, one of the ends is enclosed by 
the yoke of the other. The rod having the usual shaped 
end clamps tight around the bearing liner or bushing 
so that the liner must always turn with this rod. The 
liner extends outside the ends of this rod and on these 
outside extensions are mounted the two forked ends of 
the other rod so that the second rod has its bearing on 
the outside of the bushing clamped by the first rod, the 
first rod having its bearing directly on the crank pin 
in the usual way. 


TWELVE-CYLINDER ENGINES. 


The best method of describing the reason for the 
existence of the twelve-cylinder engine is to compare it 
with engines of lesser numbers of cylinders. Of course, 
it is very evident that, the greater the number of cylin¬ 
ders, the greater the evenness with which the power 
plant operates, but just why is this true? 

Let us consider the theory of crank effort in describ¬ 
ing the twelve-cylinder engine. In a single-cylinder 
engine four strokes of the piston are required to com¬ 
plete its cycle: the suction stroke, compression stroke, 
power stroke and exhaust stroke. Only one of these 
strokes, the third, creates power. Power is produced 
through about four-fifths of the stroke of the motor. 
Hence, in a single-cylinder engine with 5-inch stroke 
th.e piston travel for one complete cycle will be 20 
inches* and in only about 4 inches of this travel is power 
produced. 

Now let us consider the four-cylinder engine. Here 
we have one power stroke during each half revolution 
of the .crankshaft. This gives us power during 16 inches 
of piston travel (considering that the cylinders are the 
same size as in the first example), or power during 88 
per cent of the entire cycle. 

In the six-cylinder, the cylinder being the same size, 
we have 4 inches of power produced by each cylinder, 
making a total of 24 inches in power with a piston travel 
of 20 inches. This would mean that power is delivered 

120 




^ „ Section 1 

MOTOR CAR PARTS 121 

during 120 per cent of the cycle, or an overlapping of 
power occurs from cylinder to cylinder. 

Now, in the twelve-cylinder engine with the same 
size cylinders as before, we have the same 4 inches of 
power in each cylinder, or 48 inches total, with a total 
piston travel of 20 inches. This shows a very large 
overlap of power. Here the overlap is seven times as 



PACKARD TWIN SIX ENGINE 

Cut-away view showing arrangement of connecting rods on crankshaft. 


great as the six-cylinder form; in fact, it is practically 
continuous power flow. 

There is no dead center in a twelve-cylinder engine. 
The cranks are set at 120 degrees, as in the six, but the 
cylinders are set at 60 degrees, 30 in each side of the 
vertical. The crankpin attachment in these engines is 
to have the first two cylinders working on the first 
crankpin, the second two on the second pin, etc. Obvi¬ 
ously the form of the crank and the setting of the cylin¬ 
ders at an angle eliminate all dead centers. 










Section 1 

122 MOTOR CAR PARTS 

Now consider the power exerted upon the pistons. 
In a single-cylinder engine of 48 horsepower, the explo¬ 
sion of the mixture results in the striking of a terrific 
blow against the piston of 28,800 pounds. In a four- 
cylinder, 48-horsepower motor each piston receives 3 , 
blow only one-fourth as great, or 7,200 pounds. In a 
six the explosion force is only 4,800 pounds, and in a 48- 
horsepower twelve the blow is only 2,400 pounds. It is 
this small amount of hammering which makes the 
twelve-cylinder motor much more quiet and easy-run¬ 
ning. In addition to this, the small size of the pistons 
and reciprocating parts for equal power development 
allows a much stiller and stronger construction. 

The multiple-cylinder engine is relatively more effi¬ 
cient than the engine of fewer cylinders, such as one, 
two, four or six, because the lighter reciprocating parts 
increase the output per cubic inch of the cylinders. 

Any mechanic who posts himself thoroughly on the 
care and repair of fours and sixes need have no fear of 
trouble in handling the twelve-cylinder engines. They 
are virtually the same, the difference being that the 
similar parts are multiplied. 


EXHAUST MANIFOLD DESIGN. 


T. A very peculiar trouble sometimes can be traced 
to the exhaust manifold of a six-cylinder car. T.he 
length of each exhaust valve opening is about 225°. 
It will be seen that the six cylinders will be exhausting 
during a total of six times 225° or 1350°. In the two 
complete revolutions of the crank shaft necessary to 
complete the cycle and bring the first valve back to 
its exhaust opening there are but 720°, so it will be 
seen that more than one exhaust valve must be open at 
one time. 

As a cylinder is finishing its exhaust the gas comes 
out of its valve at rather low pressure. Another cylin¬ 
der near it will start to exhaust with the gas coming 
from its valve at high pressure. This raises the pres¬ 
sure in the exhaust manifold to a point where burned 
gas will be forced back into the first cylinder. 

This can be remedied only by a very large manifold, 
exhaust pipe and muffler; or, as is done in some cars, 
there may be two exhaust manifolds, one for each set 
of three cylinders. 

This condition with a small manifold will cause a 
considerable loss of power. This loss is lessened by 
having the firing order so that adjoining cylinders do 
not fire one after the other. Such firing orders would 
be 1-4-2-6-3-5, 1-5-3-6-2-4, 1-3-2-6-4-5, etc. 


123 


FIRING ORDERS. 


The firing order of an engine means the order of 
sequence in which the different cylinders fire their 
charge, always starting with number one cylinder, 
which is the one nearest the radiator. 

A single-cylinder engine has, therefore, no firing 
order; a two-cylinder engine always fires 1-2, as there 
are no other cylinders to come between; a three-cylin¬ 
der might fire 1-2-3 or 1-3-2. 

A four-cylinder engine is either arranged to fire 
1-3-4-2 or 1-2-4-3, the former order being the order most 
commonly used. 

A typical firing order for a six is 1-5-3-6-2-4, but there 
are so many possible firing orders in the six-cylinder, 
and likewise in the newer eight- and twelve-cylinder 
engines, that no regular rule can be set down. So much 
uncertainty exists that many makers have solved this 
for the repairman by attaching to the motor or to the 
dash a firing plan giving the firing order. 

There are eight possible firing orders for the six or 
eight. For the six they are as follows : 


(1) 1-2-3-6-5-4 

(2) 1-2-4-6-5-3 

(3) 1-3-2-6-4-5 

(4) 1-3-5-6-4-2 


(5) 1-4-5-6-3-2 

(6) 1-5-4-6-2-3 

(7) 1-4-2-6-3-5 

(8) 1-5-3-6-2-4 


The seventh and eighth named are the most com¬ 
monly used. 


124 


_ Section 1 

MOTOR CAR PARTS 125 

For the V-type eight-cylinder engine the following 
orders are possible: 

(1) 1R-1L-2R-2 L-4R-4 L-3 R-3 L 

(2) 1R-1 L-3 R-3 L-4R-4L-2R-2 L 

(3) 1R-4 L-2 R-3 L-4R-1 L-3 R-2 L 

(4) 1 R-4 L-3 R-2 L-4R-1 L-2 R-3 L 

(5) 1R-1 L-3 R-2 L-4R-4 L-2 R-3 L 

(6) 1R-1 L-2 R-3 L-4R-4 L-3 R-2 L 

(7) 1 R-4 L-2 R-3 L-4R-1L-2R-3 L 

(8) 1 R-4 L-2 R-3 L-4R-1 L-3 R-2 L 

Inasmuch as the last four involve different firing 
order in the two sets of four cylinders each, they need 
not be considered. The most commonly used are the 
orders (3) and (4). 

In the same way that the eight-cylinder V-type 
engine is nothing more than a combination of two 
groups of fours, so the twelve is a combination of two 
groups of sixes. The firing orders adopted are accord¬ 
ingly combinations of the groups of sixes alternating 
first from the right set of cylinders, then to the left. 

Examples are as follows : 

National twelve — 1R-6L-3L-4R-5R-2L-5L-2R-3R- 
4L-1L-6R. 

Packard twelve — 1R-6L-4R-3L-2R-5L-6R-1L-3R- 
4L-5R-2L. 

Pathfinder twelve — 1R-1L-4R-4L-2R-2L-6R-6L-3R- 
3L-5R-5L. 


The reason for not having the cylinders fire one after 
the other, according to the number of cylinders, is that 
this distributes the strain on the crankshaft more even- 


MOTOR CAR PARTS 


Section 1 
126 

ly and makes for better engine balance. Whenever a 
cylinder fires the connecting rod springs the crankshaft 
slightly. This springing would be carried from end to 
end of the shaft if the cylinders fired one after the other 
from front to back and would then be suddenly trans¬ 
ferred to the other end of the crankshaft. 

By having the cylinders firing next after each other, 
separated by one or more other cylinders, this strain is 
gradually moved along the shaft. 

It is necessary to know the firing order of an engine 
in order to run the wires from the magneto distributor 
or battery distributor to the spark plug so that the cyl¬ 
inders will receive the spark in the same order in which 
they will fire. To find the firing order of an engine, 
watch either the inlet valves or the exhaust valves, but 
not both. Turn the engine slowly until the valve on 
number one cylinder opens. Now watch, or have a 
helper watch, for the next valve to open, then the next, 
each time tabulating the number of the cylinder. In 
this way the firing order of any engine can be quite 
readily found. 


FLYWHEEL. 


D. The flywheel is for the purpose of making the 
engine run evenly from one explosion to the next, for 
that reason the fewer the number of cylinders and the 
greater the time between explosions the larger the 
wheel required. 

Flywheels are fastened to the front or rear end of 
the crank shaft by being bolted to a ring or flange which 
is in one piece with the crank shaft. There may be 
from four to eight bolts. Older forms of construction 
have the wheel fastened to the end of the shaft with one 
or more keys and nuts, the end of the shaft being either 
straight or tapered. 

When flywheels are mounted, small holes are bored 
at points in the rim that make the wheel, crank shaft, 
pistons and connecting rods just balance each other. 

R. In replacing the flywheel it must be placed in ex¬ 
actly the same position as found, and to insure this, it 
is best to mark with a center punch the proper posi¬ 
tion on the wheel and shaft or flange. Failure to do 
this causes the engine to vibrate. 

Keys must be a true, tight and perfect fit along their 
entire length and the hole through the flywheel must 
just fit over the shaft without looseness or play. Other¬ 
wise a bushing must be inserted. 

When bolting a flywheel onto a flanged shaft see 
that the depression in the flywheel fits over the flange 
exactly and that there is nothing between the shaft and 
wheel or flange and wheel. 

127 


MOTOR CAR PARTS 


Section 1 
128 

Each bolt must fit its hole exactly without looseness 
and the bolts and nuts must be drawn very tight and 
securely locked with cotter pins and castellated nuts 
or other suitable means other than lock washers. A 
loose flywheel makes a heavy pounding noise when¬ 
ever the engine runs and must be tightened imme¬ 
diately. 


FRAME. 


D. Automobile frames are usually made from thin 
plates of steel pressed into a channel section and 
formed to make the shape desired .under heavy presses 
while the metal is cold. They are called cold pressed 
channel steel frames. 

Some frames are of wood or of wood enclosed by 
metal. 

Truck frames .are made from channel, “I” beam or 
angle steel. 

T. A bent frame may be straightened cold if the 
bend is long and gradual but if the bend is sharp the 
frame will crack. To straighten a frame cold it is 
necessary to use jacks, bars and chains to force it 
back into shape. To straighten sharp bends the frame 
must be heated by means of a brazing torch or an 
oxy-acetylene torch when the frame is allowed to re¬ 
main in the car, or in a forge fire if the frame is taken 
out of the car. 

When the part of the frame where the bend is has 
reached a red heat it may be easily bent and hammered 
or pulled back into shape, with the help of large bars, 
wrenches and heavy hammers. 

Allow the frame to cool slowly and then heat it 
again until it just reaches the heat where it will no 
longer attract a magnet, then let it cool slowly from 
this point while covered with asbestos sheeting. This 
last heating is to restore the strength of the steel. 

129 


Section 1 

130 


MOTOR CAR PARTS 


A cracked frame may be welded while in the car 
by means of the oxy-acetylene welding torch. 

If the frame cannot be welded, repair it by making a 
patch of steel of the same or greater thickness than 
the frame itself and shaping this patch so that it just 
fits inside the frame where it is cracked. Make the 
patch touch the vertical and horizontal flanges of the 



STRAIGHTENING A BENT FRAME WITH A JACK AND STEEL 
CHAIN OR CABLE. 

frame evenly at all points and have it extend at least 
six inches each way from the crack. This piece is then 
riveted in place with five-sixteenth inch rivets placed 
two inches apart and driven in hot with heavy blows of 
the hammer. 

A frame broken in two may be patched as given 
above except that the patch should extend a foot each 
side of the crack and in addition to this a truss should 














Section 1 

MOTOR CAR PARTS 131 

be fitted to support the frame where broken. This 
truss is made from a seven-sixteenth inch diameter 
cold rolled steel rod about six or seven feet long. A 
ring must be fitted to each end of this rod or it may 
have the end bent into a ring. This ring is to be 
bolted to the frame on the lower side about three 
feet from the broken place. The other end of the rod 
will be bolted to the frame about the same distance 
the other side of the break so that the rod runs along 
under the frame past the broken place. A solid piece 
of steel at least two inches thick must be made and 
placed between the frame and the rod so that the piece 
comes directly under the broken place and supports it. 
A turnbuckle may be placed in the rod so that it may 
be drawn tight, giving the broken place a firm support. 


FUEL FEED. 


Gravity. The simplest method in use for causing 
a flow of fuel from the tank to the carburetor is that 
known as the gravity system, in which the tank is 
at a point sufficiently higher than the float chamber 
of the carburetor to cause a natural flow. This allows 
three locations for the tank: under the driver’s seat, 
on the dash or in the cowl -of the hood and directly 
over the engine. 

The demand for cars hung low to the ground has 
made it necessary to lower the seats to a point at 
which it is difficult to find sufficient room under the 
seat for a tank of the proper size and capacity. Un¬ 
less the tank can be placed at a proper height the flow 
to the carburetor may be stopped on a steep hill when 
the bottom of the tank may be below the level of the 
carburetor float chamber. 

Care must be used to see that air can find its way 
into the tank to take the place of the gasoline that 
flows out. To allow this, there is a small hole at some 
point, usually in the filler cap, which must be kept 
open. 

Care must also be used to see that all joints- in the 
piping are tight and that the carburetor does not 
“flood,” as any form of leakage will cause the entire 
contents of the tank to flow out, wasting the fuel and 
making a source of danger from fire. 

Pressure. The desire for positive fuel feed regard¬ 
less of the quantity of fuel in the tank or the location 

132 


MOTOR CAR PARTS 


Section 1 

133 


of the tank has led to the adoption of the pressure feed. 
This allows the tank to be located at any convenient 
point on the car, either under the seat or at the rear 
of the frame. The rear location allows greater acces¬ 
sibility for filling, although the tank is exposed to more 
damage from accident. 

Pressure is supplied by a plunger pump or from 
the exhaust gases. The plunger pumps usually operate 
from the crank or valve operating shaft, being fitted 
with ball or poppett types of check valves. Pressure 
is taken from the exhaust gases by causing the gas to 
operate a plunger or a flat disc of metal called a dia¬ 
phragm. This metal is placed in a housing in such 
a way that the exhaust pressure reaches one side and 
causes the metal to have a slight buckling movement 
(like the bottom of some pans when pressed up and 
down). This movement of the diaphragm acts as a 
pump plunger, forcing air into the tank or drawing 
fuel from the tank. 

Plunger pumps of all types require that their valves 
be kept perfectly tight and free from dirt or soot from 
the air or exhaust gases. All piping from the pump 
to the tank must be kept tight or no pressure will be 
delivered into the tank. 

As the pressure of air is raised in the tank the fuel 
is caused to flow out of another pipe leading to the car¬ 
buretor. To start the car after the tank has been 
opened or at any time when no pressure remains in 
the tank recourse is had to a hand pump. A pressure 
of one to three pounds of air to the square inch is ample 
in all cases. 

Vacuum. A comparatively new method of causing 
the fuel to flow from a tank below the level of the 


Sc-ction 1 

134 


MOTOR CAR PARTS 


carburetor is that known as the vacuum system in 
which advantage is taken of the suction in the inlet 
piping caused by the downward movement of the pis¬ 
tons drawing air through the carburetor. 

The parts required comprise a tank, usually mounted 
on the engine side of the dash. This tank is divided 
into two chambers, upper and lower. The upper cham¬ 
ber is connected to the intake manifold, while another 
pipe connects it with the main fuel tank. The lower 
chamber is connected with the carburetor. The in¬ 
take strokes create a vacuum in the upper chamber, 
and this vacuum draws fuel from the tank. 

As the fuel flows into this upper chamber it raises a 
float valve. When this float valve reaches a certain 
height it shuts off the vacuum valve and opens a valve 
leading to the outside air, allowing the gasoline to 
flow down into the lower chamber. As the fuel flows 
out of the upper chamber the float valve drops, open¬ 
ing the vacuum valve and causing the upper chamber 
to refill. 

The lower chamber always has an opening leading 
to the outside air, so that fuel can flow to the car¬ 
buretor as required. 

Care must be used to see that the pipe leading from 
the inlet piping to the vacuum tank is tight and that 
all joints in the upper chamber are tight at all times. 
There must be no leaks in the pipe leading from the 
upper chamber to the fuel tank, but the fuel tank must 
have a small opening through the cap, or at some point 
that allows air to enter the tank to take the place of 
the gasoline drawn out. 

This system of feed is also made to handle the lubri¬ 
cating oil in the same manner as the fuel is handled. 


MOTOR CAR PARTS 


AIR VENT—* 


f FROM 
v GASOLINE 
TANK 


TO INTAKE 
MANIFOLD 



PLUG 


TO CARBU¬ 
RETOR 


VACUUM FUEL FEED SYSTEM. 
(Stewart-Warner.) 


Section 1 

135 















































GEARS, TIMING. 


D. Timing gears are those gears placed in the engine 
connecting the crank shaft with the cam shaft or the 
shaft that moves the parts opening and closing the 
valves, running the magneto, pump or other part. The 
shaft operating the valves always moves at just half 
the speed of the crank shaft in a four cycle engine and 
at the same speed in a two cycle. Therefore, in a four 
cycle engine the gear or sprocket on the crank shaft 
will be exactly half the size of the one on the cam or 
valve operating shaft. 

Timing gears are for the purpose of regulating 
and controlling the time during the piston strokes at 
which the fresh or burned gases are admitted to or 
expelled from the cylinder. 

R. The correct replacement of the timing gears on 
the engine is fully covered under Valve Timing. 

T. Noise from the timing gears may be caused by 
worn or broken teeth in the gears, gears loose on their 
shafts, from the gears touching the covers or housings 
or bolts, or the gears may be crooked on the shafts. 

Worn or broken teeth require that the gear be re¬ 
placed by a new one. The new gear meshing with 
the old ones will make a humming or ringing noise, 
but this cannot be helped. Use will correct it as the 
gears wear to a fit. 

If the gears are found to be loose on the crank, cam, 
valve or magneto shaft they should be removed and 
the hole in the gear should be made to fit over the end 
136 


Section 1 

MOTOR CAR PARTS 137 

of the shaft perfectly. This may require reboring of 
the gear or that the gear be bored out and a bushing 
inserted, this bushing then being bored the correct 
size and shape. The end of the shaft may have to be 
refinished on the lathe. 

The keyway in the gear or shaft may be worn larger 
than the key in which case the keyways must be filed 
or chiseled to a regular shape and new keys fitted that 
exactly fit the keyways. 

The nut or the pin that holds the gear onto the shaft 
may not be tightly in place or the threads or holes may 
be worn. This makes it necessary to re-thread the 
shaft or else use washers under the. nut so that the 
remaining threads can be used. Pin holes will have 
to be reamed to a larger size and new pins inserted. 

Should the gear rub against a part of the case or 
cover or a bolt or nut, it is probably caused by the gear 
being loose or out of line. A gear that is bent in itself 
must be replaced with a new one. After correcting 
these conditions if the noise still continues, file or 
grind the projecting parts away. 

If the gears run out of line after being tightened as 
directed the shaft may be bent or the gear may be 
crooked on the shaft because of dirt in a tapered hole. 
This condition may also be caused by a key poorly 
fitted or too large, by a nut that has been cross threaded 
or started on crooked or by carelessness in placing the 
gear on the shaft. 


MODERN INLET MANIFOLDS. 


One of the most noteworthy changes in the power 
plants within the last two years has been the design of 
the inlet manifolds. The real importance of proper 
design in this part was not forcefully realized until the 
advent of very poor gasoline. Carburetor makers came 
forth in an effort to offset the trouble caused by the 
poor fuel, and found they could not handle the situation 
in their instruments alone. Then came the awakening 
of the engineers and the complete redesigning of inlet 
systems. 

Almost universally, in modern engines, the inlet 
manifold is so located that it is heated by the exhaust 
gases. There are very few power plants of the newer 
types in which the two manifolds are on opposite sides 
of the cylinders. One of the most common methods 
employed is to run the exhaust manifold along the out¬ 
side of the inlet manifold. An example of this is shown 
in the illustration of the new Nash Six plant. 

Another method of heating the manifold is by the 
hot-water treatment. In several of the V-type engines, 
where the carburetor and inlet manifold are located 
between the two sets of cylinders, the inlet manifold 
itself is jacketed and the water which passes through 
the engine is turned into this jacket. The heat of this 
water maintains a fairly uniform temperature for the 
incoming gases. 

Another adaptation of the water-heating treatment is 
to place the inlet manifold directly within the cylinder- 
138 


_ m _ Section 1 

MOTOR CAR PARTS 139 

head casting, with hot-water jackets surrounding it on 
all sides. 

There is no longer a long reach between the car¬ 
buretor and the inlet valves. This is being shortened 
to the greatest possible extent in order to eliminate con- 



ARRANGEMENT OF INLET MANIFOLD ON NEW NASH SIX 

densation of the gases between the carburetor and the 
cylinders. 

In some types there is a web cast into the inlet mani¬ 
fold where the carburetor enters. This is really a gas 
splitter. The web serves to direct half of the gas in one 
direction in the manifold and half in the opposite direc¬ 
tion, assisting in apportioning the gases correctly and 
getting the mixtures into the cylinders with great 
speed. 

Where the web is put in, another scheme is often 
used, consisting of the introduction of a “hot spot.” 












Section 1 

140 MOTOR CAR PA^TS 

This hot spot is more fully described elsewhere under 
the discussion of heating. It is a thin wall of cast iron 
kept at high heat by the action of the exhaust gases, 
serving to break up the incoming fuel and heat it to the 
most efficient point for perfect combustion. 

C. The piping from the carburetor to the cylinders 
must be kept perfectly air tight at all points and at all 
times. To prevent vibration causing breaks and leaky 
joints the carburetor, and if possible the piping itself, 
should be steadied and supported by braces and clamps 
running to the engine (but not to the frame). 

R. In replacing an inlet manifold the greatest care 
must be used to make every joint perfectly tight by 
applying well fitted, new and perfect gaskets at all 
points, these gaskets being coated with shellac if pos¬ 
sible. Before the manifold is fastened on, every joint 
and thread should be tested for leakage , by covering 
all openings except one with rubber stretched over a 
piece of wood and clamped or tied over the openings, 
then placing the pipe, or most of it, under water and 
blowing into the free opening while watching for bub¬ 
bles. Every section of the piping must be tested in 
this way as a precaution. 

T. One of the commonest of all car troubles is due 
to air leakage into the mixture, after it leaves the car¬ 
buretor mixing chamber, through holes or cracks in 
the inlet manifold. 

These leaks may come from defective gaskets at any 
joint or from holes in the manifold. 

A leaky inlet manifold makes it practically impos¬ 
sible to adjust the carburetor for different speeds. 

The easiest way to detect leaks when the manifold 
and carburetor are in place is to take a small squirt 


Section 1 

MOTOR CAR PARTS 141 

can filled with gasoline and while the engine runs squirt 
the gasoline around all joints and all along the whole 
manifold. This should not affect the running of the 
engine, but if there are any leaks the gasoline will be 
sucked into the piping and will usually make the engine 
run faster or slower or the engine may stop. The suck¬ 
ing of the gasoline may also be heard. The leaks must 
be exactly located and soldered or re-gasketed. 

Some of the older cars have manifolds so long that 
the gasoline now used condenses along the walls of 
the pipe and thus spoils the mixture. The only remedy 
is a shorter pipe. 


LUBRICATION. 


D. Every moving part of a car must be lubricated 
by some means. The. engine is supplied with cylinder 
oil which is forced by systems of pumping or splash 
or gravity flow to the bearings and sliding parts. The 
fan and pump bearings are supplied with grease cups 
or oil holes. The magneto bearings are packed in 
vaseline. The shafts on the engine all have grease 
cups when outside the crank case. 

The clutch has its bearings fitted with grease cups 
or else it operates in a closed case and in an oil bath. 
The universals are packed in grease and have grease 
cups, the change speed or transmission gears operate 
in a case having light transmission grease or cylin¬ 
der oil, the rear axle has transmission grease or cylin¬ 
der oil in its housing, the wheel bearings are packed 
with grease and so is the steering gear. The axle pins 
and the spark and throttle and brake control parts are 
all fitted with grease cups or oil holes. 

Oils and greases and lubricants are treated else¬ 
where. 

A. The only types of engine lubrication requiring 
adjustment are those in which there are several pumps 
or one pump contained in a case or oiler carried out¬ 
side the engine crank case and driven by power from 
the engine. On the outside of the case there is usually 
some part that rises and falls with the pump plunger 
and on or near this part is a nut or small screw that 
may be turned one way or the other to give the pump 

142 


, Section 1 

MOTOR CAR PARTS 143 

a greater or less stroke, delivering more or less oil 
into the pipes. On top of these oilers are usually small 
pipes which have a screw needle valve in them. Open¬ 
ing this needle by turning the screw allows the oil 
to come from the pipe and shows how much oil is 
being pumped into that pipe. 

Pipes leading to the crank case should give about 
two drops about every five seconds with the engine 
running at a moderate speed. Pipes leading to the 
cylinders should give about the same, or possibly 
three drops. Pipes leading to bearings should have 
one drop every ten seconds. Should this adjustment 
cause the engine to smoke, reduce the oil feed to the 
cylinders or crank case. As long as the engine does 
not smoke at the exhaust it is safe to increase the 
oil feed. 

When the whole engine is oiled from one feed the 
delivery of oil should be started at four or five drops 
every five seconds and increased until the engine 
smokes and then gradually cut down until the smoking 
is stopped. 

Other forms of oilers in use have arrangements so 
that the engine parts can use what they need, the bal¬ 
ance being returned to the tank. The only care needed 
by these types is that the oil be kept in the tank or 
reservoir. 

Oilers, oil tanks and oil reservoirs, whether on the 
crank case, in the engine or separate from the engine, 
always have some means of showing how much 
oil they contain. There may be small pet cocks fitted 
at different heights on the tanks, there may be a glass 
tube which carries the same height of oil as is in the 
tank or there may be a tube carrying a plunger with 


Section 1 


144 


MOTOR CAR PARTS 


an extension or marker at the top in sight* of the 
driver or which can be seen by raising the hood. 
Other types have the oil flowing through a glass bowl 
or tube on the dashboard or on the crank case; if no 
oil is flowing the tank must be replenished imme¬ 
diately. 



DETAILS OF REO OIL PUMP 


Oil tanks having indicators of any kind should not 
be filled to the top as this will, in most cases, give 
the engine too much oil. 

Parts of the car requiring lubrication daily are as 
follows: 

Engine crank case or separate oiler, cylinder oil. 


























MOTOR CAR PARTS 


Section 1 

145 

Clutch main bearing and release bearing, cup grease. 

Parts requiring attention weekly are as follows: 

Starting crank bearing or all cups and oilers on the 
lighting and starting dynamo and motor, cup grease. 

Oilers, cylinder oil. 

Fan bearing, grease or oil. 

Magneto shaft, cup grease. 

All spring bolts and shackles, cup grease. 

Water pump shaft, cup grease. 

Timing gear grease cups, cup full of cup grease. 

Overhead valve operating parts, cylinder oil. 

Steering gear case, cup grease, full cup. 

Gear shifting parts, cup grease. 

Clutch release shafts, etc., cup grease or cylinder oil. 

Parts requiring attention twice a month are as 
follows: 

Steering knuckle bolts, cup grease. 

Steering cross rod ends, cup grease. 

All brake operating parts, cams, pins and shafts, cup 
grease or cylinder oil. 

Parts requiring attention every 1,000 to 1,500 miles: 

Magneto oil cups, light machine oil. 

Multiple disc clutch housing, cylinder oil. 

Wheel and steering pivot bearings, light transmis¬ 
sion grease. 

Steering fore and aft rod or drag link ends, cup 
grease. 

Transmission case, light transmission grease or cyl¬ 
inder oil. 

Rear axle and differential housing, light transmis¬ 
sion grease or cylinder oil. 

Dynamo and starter gearing or chains, cup or trans¬ 
mission grease. 


Section 1 

146 


MOTOR CAR PARTS 


Parts to be lubricated every 2,000 to 3,000 miles: 

Spring leaves, cylinder oil and graphite. 

Universal joints, cup grease and graphite. 

Dynamo and starting motor bearings, vaseline. 

T. With Any Type— 

1. Oil level too low. Causes heating. Add oil im¬ 
mediately. 

2. Piping clogged, leaking, bent or has loose joint. 
Remove pipe and blow toward end from which the 
obstruction entered the pipe. Straighten, pack or 
tighten joint. 

With Circulating Systems— 

1. Oil dirty, old or worn out. Replace with fresh 
and wash out reservoir every 1,000 miles running. 

2. Filter screens dirty. Clean with gasoline and 
brush. 

3. Pump has broken drive or is worn out. Replace 
drive or entire pump. 

4. Pump valves not seating. Remove and clean seat 
and grind with powdered glass and oil if necessary to 
make tight. 

5. Pump springs broken or stuck. Replace with 
new or release if sticking. 

6. Pump plunger sticking, dirty or worn. Clean and 
replace, if necessary, with new plunger. 

With Force Feed Systems. (Having separate pumps 
and pipes.)— 

1. Valves out of order. Examine and clean or grind. 

2. Pipes leaking pressure or oil. Solder or replace 
with new pipe. 

3. Pumps out of order (see under “circulating sys¬ 
tems”). 


Section 1 

MOTOR CAR PARTS 147 

4. Leaks in piping or valves inside of oiler. Solder, 
pack or replace. 

Vacuum Feed Systems— 

1. Valve in bottom of tank sticking open or closed 
at wrong time. 

2 . Air leaks into tank past cap or other leak. Vacu¬ 
um feed parts must be kept perfectly tight. 

Sight Feeds— 

1. Clogged. Take apart and clean. 

2 . Leaking oil or pressure. Tighten leaky joints or 
replace gaskets. 

Tanks— 

1. Leaks in cap, plug or tank proper. Solder or 
prevent leak. 

Drive Troubles— 

1. Belt oil soaked or loose. 

2 . Ratchet has worn teeth. Replace. 

3. Pulleys loose on shafts. 

4. Worm has worn teeth. 

5. Cams worn or loose on shafts. 

Oil— 

Of poor quality. The worst possible “economy.” 
Too heavy or too light. Depending on engine type. 
Old or dirty. Should be replaced with all fresh 
supply. 

All Oiling Troubles Cause— 

Heating, binding, dragging, squeaking, loss of 
power. 


i i 


NOISY OPERATION. 


Knocking or Pounding— 

1. Spark too far advanced. Run it retarded more. 

2. Pre-ignition. Firing before top center, caused 
by red-hot parts or pieces of carbon in cylinder. May 
come from too rich a mixture, or cylinder may need 
cleaning of carbon. 

3. Connecting rod lower bearing loose. Adjust. 

4. Main crankshaft bearing loose. Adjust. 

5. Wrist pin bearing loose. Replace bushing. 

6. Bearing loose in its cap. Replace or fasten. 

7. Motor loose in frame. Tighten bolts. 

8. Cylinder loose on crank case. Tighten bolts. 

9. Valve strikes spark plug. Use shorter plug. 

10. Worn pistons. Put in new ones. 

11. Worn cylinders. Rebore and get new pistons. 

12. Compression too high. Raise the cylinders by 
putting a gasket under them on the crank case from 
one-eighth to three-eighth inch in thickness. 

13. Loose flywheel. Tighten bolts, or replace key. 

14. Flywheel on wrong. Unbalances the engine. 

15. Flywheel wobbles. Straighten. 

16. Broken ball or roller bearing. Replace with a 
new one. 

17. Timing gears worn. Replace with new ones. 

18. Sprung crank shaft. Straighten in a machine 
shop. 

19. Connecting rod strikes edges of cylinder holes 
in crank case. File sides of holes larger. 

148 


Section 1 

MOTOR CAR PARTS 149 

20. Loose pieces in the crank case. Remove. 

21. Connecting rod striking some part of crank case. 
Remove the obstruction. 

22. Oil pump clogged or not working. Clean. 

23. Timing gears loose on shaft. Fit new keys or 
keyways. 

24. Cam loose on shaft. New shaft or new pins. 

25. Loose counter weights. Tighten. 

Hissing or Wheezing— 

1. Gas leaks around the priming cups, spark plugs, 
valve caps, or any broken or defective gasket. Re¬ 
place the gasket. 

2. Gas leaks past loose piston. Makes crank case 
hot. Fit new piston. 

3. Gas leaks past broken ring. Makes crank case 
hot. Fit new ring. 

4. Cylinder wall scratched (scored). Rebore cylin¬ 
ders and fit new piston. 

Slapping or Threshing— 

L Pistons or cylinders worn. Replace the worn 
parts. 

2. Engine re-assembled wrong. Put parts together 
right. 

3. Worn valve stem guides. Replace the bushings. 
Grinding, Scraping, or Grating— 

1. Flywheel touches some part. Move whatever is 
touching. 

2. Lack of oil somewhere. Oil. 

3. Broken ball or roller bearing. Replace. 

4. Worn gear teeth. Replace. 

5. Loose wrist pin. (Scrapes cylinder walls.) 
Tighten. 


Section 1 

150 


MOTOR CAR PARTS 


6. Broken piston ring. (Scrapes cylinder walls.) 
Replace. 

7. Tight piston rings. File off ends of rings. 

Clicking or Rattling— 

1. Fan touching other part Bend the fan or move 
the other part. 

2. Too much valve stem clearance. Change adjust¬ 
ment to thickness of thin card. 

3. Metal pieces in the crank case. Remove. 

4. Worn valve stem guides. Replace the bushings. 

5. Loose or worn valve parts. Replace or tighten. 

6. Loose cam shaft bearings. Adjust or replace. 

Popping or Spitting— 

1. Too weak a mixture. Adjust the carburetor. 

2. Inlet closes too late, or the exhaust opens too 
early. 

Squeaking— 

1. Lack of oil. Oil. 

2. Hot bearings. Oil or grease. 


PISTON RING. 


D. These are cast iron rings that fit into a slot or 
groove cut around the outside of the piston. These 
rings are slit through on one side so that they spring 
out against the walls of the cylinder and prevent the 
gas from blowing through between the piston and 
cylinder. There may be from two to four ring grooves 
on each piston. 

C. The greatest care must be used in removing and 
replacing ihe rings inasmuch as they are extremely 
brittle. Spread them open only enough to slip over 
the piston. Any more will almost surely result in 
breakage. 

A. New piston rings must be fitted to the cylinder 
as follows: 

First. Clean the slots of all carbon and foreign mat¬ 
ter and examine them closely to see that the inside 
corners are square and that the top and bottom of the 
slot are parallel to each other and have no taper. If 
the slots are worn out of shape the piston must be 
placed in the lathe and the slot turned out to a larger 
size (one-sixteenth inch wider) than the original size. 
Never make a size other than one-sixteenth, one- 
eighth or one-fourth part of an inch; that is, never 
make a size that has to Le measured by thirty-seconds 
of an inch as it is difficult to secure new rings of these 
sizes. 

Second. Secure a ring of the right width and of the 
right diameter for the bore of the cylinder. 

151 


Section 1 

152 


MOTOR CAR PARTS 


Third. Without placing the ring over the piston, 
stick it edgewise in the slot ,and toll,.jit all the way 
around the outside of the piston and in the slot. It 
should fit easily all around, but without play or bind¬ 
ing at any point. If it does not fit, file the high spots 
carefully with a small fine flat file. 

Fourth. Carefully spring the ring over the piston 
and let it drop into the slot. Now try to push the 
piston into the cylinder. If the ring is too large to let 
the piston enter, remove the ring from the piston and 
file a very little from the ends of the ring at the slit 
on one side, being careful to keep the edges of the slit 
true and parallel to each other so that when they touch 
they match exactly. 

Fifth. Cover the outside of the ring with a thin coat 
of Prussian blue and while holding the piston and con¬ 
necting rod in exactly the position they will occupy 
when the engine is assembled slide the piston and ring 
into the cylinder. Do not slide the piston farther 
than it will travel when in use. Take the piston out 
again and wherever the blue has been rubbed ofif dress 
away a little of the outside surface of the ring with a 
fine file or piece of emery cloth fastened to a piece of 
wood. 

Sixth. Repeat this operation until almost all of the 
blue is rubbed off after putting a fresh coat on each 
time and then follow the same method for each ring 
needed. 

In case an old ring has lost some of its spring and 
does not touch the cylinder wall at all points gas is 
allowed to leak past the ring. The places of leakage 
can be recognized because the outside of the ring will 


MOTOR CAR PARTS 


Section 1 

153 


be dark brown or black at these places. To re-fit an 
old ring— 

First. Carefully remove the ring from the piston and 
hold the outside surface that touches the cylinder wall 
on some flat, smooth steel surface. 

Second. With a machinist’s ball peen hammer strike 
the inside of the ring a great many very light blows 
with the ball end of the hammer. Strike so that the 
part of the ring being struck is exactly between the 
hammer head and the steel surface and always move 



the ring into this position before striking, otherwise 
the ring will be broken. Strike the ring opposite the 
point where it is slit and for one or two inches each 
way from that place. 

Third. Watch the opening in the ring while striking 
and when the slit is open from one-eighth to one-fourth 
of an inch more than when you started the ring has 
been spread enough. 

Fourth. Fit the ring as directed for new rings. 

R. Piston rings are very easily broken in removing 
and replacing. Lift up one end of the ring with a 












MOTOR CAR PARTS 


Section 1 

154 

small screwdriver until you can slip a thin piece of 
metal (a piece of old hack saw blade is good) under 
the ring. This piece should point up and down on the 
piston and should be slid around the piston until it is 
directly opposite the opening in the ring and on the 
opposite side of the piston from the opening. 

Now lift the end of the piston ring again very care¬ 
fully and slip another metal strip under the ring. 
Leave this piece near the opening and place a third 
piece under the other end of the ring a little ways from, 
the opening. 

By moving the pieces of metal back and forth you 
can raise the ring entirely out of the groove and you 
can then slide the ring up on the pieces until it comes 
off the piston. 

To replace the ring open it just enough to slip over 
the top of the piston and then place the metal strips 
in the same positions as when you removed the ring. 
Slide the ring down until it comes to its groove and 
then take the metal strips out letting the ring into 
its groove. 

Take the top ring off first and replace it last. 


LOSS OF POWER. 


If the engine or some of the cylinders have little or 
no compression— 

(a) You can test the compression of each cylinder 
by turning the starting crank or the flywheel and notic¬ 
ing the resistance as you come to the corresponding 
stroke of each cylinder. 

(b) If the engine has more than one cylinder, open 
the pet cocks, or remove the spark plugs from all but 
one cylinder. Then turn the engine over and notice 
the resistance to turning at one point. The crank or 
flywheel should spring backward when you let go of 
it, if the compression is good. 

(c) If the crank or flywheel will not spring back but 
stands still, look for the following troubles: 

1. Leaks around the spark plugs. (Test for leaks 
by putting cylinder oil on the joint and turning the 
engine over. Bubbles will show leaks.) If the plugs 
have gaskets, replace with new ones. If the engine 
uses one-half inch standard plugs, look for broken 
threads, or cracks, or holes in the part the plug screws 
into. This will require a new plug, or a new cap. 

2. Broken spark plug porcelain. Allows gas to leak 
out. Put in new porcelain. 

3. Spark plug insulation loose. Tighten packing nut 
slightly. 

4. Leaks around valve caps. Put on new gaskets. 

5. Leaks around gaskets anywhere near the com¬ 
bustion space. Put on new gaskets. 

155 


Section 1 

156 


MOTOR CAR PARTS 


6. Dirt or carbon on valve face or seat. Take valve 
out and clean face and seat with fine emery cloth. 

7. Valve stem sticking. Remove the valve and clean 
the stem. 

8. Valve stem warped (bent). Test by rolling the 
stem on a flat surface. Get a new valve and stem. 

9. Valve pitted or burned. Grind in. 

10. Valve stem broken. Needs new springs, or if 
out on the road, place a washer between the ends 
temporarily. 

11. Valve head cracked. New valve. 

12. Valve seat cracked. New valve cage, or new 
cylinder casting. 

13. Too much space between valve stem and lifter. 
Adjust to thickness of wrapping paper. 

14. Ends of valve lifter, or push rod, worn hollow. 
Very difficult to locate. New ends or new lifters. 

15. Valve adjustments loose (adjusting nuts). Set 
properly and tighten. 

16. Threads stripped on valve adjusting parts. New 
parts. 

17. Valve spring fastenings loose. Tighten, or re¬ 
place. 

18. Shoulder on valve stem. Dress down with fine 
file or emery cloth until the stem has no ridges. 

19. Shoulder on valve face. Dress in a lathe, or 
with a fine file. 

20. Weak valve spring. All the inlet valve springs 
of one engine should have the same strength, and all 
the exhaust valve springs should have the same 
strength. Test the springs by placing them end to end 
and pressing them together. If one compresses more 
than another, it should be replaced with a new one or 


Section 1 

MOTOR CAR PARTS 157 

else have washers placed under it until the strength is 
equal. 

21. Piston ring openings directly opposite one an¬ 
other. Space them evenly around the piston. 

22. Piston rings not bearing evenly on the cylinder 
walls. Cover the outer face of the ring with Prussian 
blue and push the piston up into the cylinder. Wher¬ 
ever the blue is rubbed off must be dressed down with 
a very fine file or emery cloth and then tested again 
until all blue is scraped off. See Piston Rings. 

23. Cylinder walls scored (scratched). Rebore, or 
get new cylinders and new rings. 

24. Cylinders cracked. Weld (oxy-acetylene flame), 
or get new cylinders. 

25. Piston head cracked. New piston. 

26. Valve stem guides worn loose. New guides or 
place bushings in guide holes. 

27. Valve stem worn. New valve and stem. 

28. Timing gears loose on shaft. New keys or key- 
ways. See Timing Gears. 

29. Sprung cam shaft. Straighten in a lathe, or get 
a new one. 

30. Worn cams, rollers, roller pins, tappetts, push 
rods, push rod guides, or cam shaft bearings. New 
cams, rollers, roller pins, push rod guides, or cam 
shaft bearings. 

It has been taken for granted that the valves are 
properly timed. This should be the first thing to look 
at if you have any reason to believe that they are not 
right. See Valve Timing. 


RADIUS ROD. 


D. Radius rods are fitted to each side of the car and 
run from some part of the frame, or part fastened to 
the frame, to the ends of the axle or axles or points 
near the axle ends. 

Their purpose is to keep the axles parallel to each 
other and at right angles to the length of the car. In 
shaft driven cars they are made solid from end to end 
but in chain drive cars the radius rods are fitted with 
turnbuckles or clevis or yoke ends so that their length 
may be adjusted to take up the wear of the chains. 

C. Radius rods should be kept straight at all times 
and they should be fitted so that the front and rear 
axles are parallel to each other. 

A. Radius rods may be adjusted by turning the 
front wheels until they point straight ahead. Now 
measure the distance from the front to the rear hubs 
on each side of the car and lengthen or shorten the 
rods until this distance is the same on each side. 


158 


SPARK AND THROTTLE CONTROL. 


D. On the steering wheels of most cars are mounted 
two short levers which are used to control the amount 
of throttle opening between the carburetor and cylin¬ 
ders and the spark advance or time during the stroke 
at which the spark is made to occur in the cylinders. 
Some cars have only the throttle lever on the wheel, 
the time of the spark remaining the same at all speeds. 
Other cars have no levers on the wheel, the spark time 
remaining constant and the throttle being controlled 
from a small foot pedal called the “accelerator.” 

Some cars have a small lever or handle on the 
steering wheel or steering column for controlling the 
amount of air admitted to the manifold through extra 
air inlets, or the proportion of hot and cold air may 
be regulated by a lever at this point. 

These levers and all parts that connect them to the 
parts they control are classed under “spark and throttle 
control. ,, 

C. Lost motion in these parts is very annoying to 
the driver and should always be removed as soon as 
noticeable. It may be caused by the small gears or 
sectors or arms becoming loose on their shafts or rods. 
They are held by set screws or by clamping the hub 
with a screw or bolt. Looseness is also caused by 
worn pin or bolt holes, loose ball and socket joints or 
by the levers being so placed on the rods that they 
work on a dead center without giving any lengthwise 
movement to the rod they should move. 

159 


Section 1 
160 


MOTOR CAR PARTS 


A. Some cars have the spark retarded and the 
throttle closed when the hand levers are nearest the 
driver, this being the commonest arrangement. Oth¬ 
ers, however, have the spark retarded and the throttle 
closed with the levers farthest from the driver. Still 
others have one lever toward the driver, usually the 
throttle, and the other lever away from him, with the 
spark retarded and throttle closed. 

Usually the short or lower lever will operate the 
spark advance while the long or upper lever operates 
the throttle. Other cars, however, have this order 
just reversed. 

If there are three levers on the steering wheel or 
column one of them will be for admitting extra air 
to the inlet manifold, for admitting more or less hot 
air to the carburetor or for operating the electric 
starting motor. 

Before setting any of these levers it will be neces¬ 
sary to find which lever was intended for each opera¬ 
tion and what position that lever should be in to re¬ 
tard the spark, close the throttle, shut off the air, etc. 

Alterations in these parts may be made by loosen¬ 
ing one or more of the small gears or arms under 
the hood and re-setting the parts before tightening the 
gear or arm. 

The gears or levers, one or more, should be loosened, 
the spark and throttle levers placed in the retarded 
and closed positions and the magneto breaker or timer 
placed in the retarded position and the throttle closed. 
The gears or levers should then be tightened. 

If the car is well designed and the parts properly 
assembled the spark lever will move from end to end 
of its travel while the breaker box or timer moves 


MOTOR CAR PARTS 


Section 1 
161 

from fully retarded to fully advanced. The throttle 
lever will move its full travel while the throttle passes 
from closed to wide open. 


SPRINGS. 


D. The springs used for supporting the frame of 
the car on the axles are almost always made from long 
flat leaves and are called leaf springs. 

According to the shape of the spring or the parts 
of the spring they are divided into several classes. All 
classes are denoted by the part of an ellipse that they 
make. An ellipse is a flattened circle or an oval. 

A spring made of two parts placed one over the 
other and hinged at the ends so that the whole is oval 
shaped is called a full elliptic spring. One end is on 
the axle, the other on the frame. 

A spring in one piece like one-half of the full-elliptic 
is called a half-elliptic or semi-elliptic. The axle is 
under the center of the spring and the frame carried 
at each end. 

A spring formed of a semi-elliptic part with half of 
another semi-elliptic above it is called a three-quarter 
elliptic spring. The axle is mounted near the center 
of the half-elliptic lower part, the end of the upper 
quarter-elliptic is hinged to the rear end of the lower 
part, the front of the lower part fastens to the frame 
and the other end of the upper quarter fastens to the 
frame. 

If the upper part of a three-quarter elliptic spring 
is longer than one-quarter of the oval the spring is 
called a seven-eighth elliptic. 

Springs formed of half of a semi-elliptic are called 
quarter-elliptic springs. They carry the axle at the 
162 




MOTOR CAR PARTS 


Section 1 

163 



FORMS OF LEAF SPRINGS. 

F, Full elliptic; H, Half or semi-elliptic; T, Three-quarter elliptic; S, 
Seven-eighths elliptic; C, Quarter Elliptic; P, Platform. 


12 











Section 1 

164 MOTOR CAR PARTS 

thin end and are mounted on the frame at the other 
end. 

A spring that is between a half and a quarter-ellip¬ 
tic in length is called a cantilever spring. It carries 
the axle at the small or thin end and is fastened to the 
frame at two points near the other end. 

Parts that are used with the springs in mounting 
are: Spring bolts, the bolts that pass through the ends 
of the spring. Spring clips, are U shaped pieces, 
threaded on each leg, that go over the spring with the 
threaded ends through the axle. They hold the springs 
to the axles or frame brackets. 

Spring brackets are pieces that carry the springs 
and are fastened to the frame. 

Spring eyes are the holes in the ends of the springs 
through which the bolts pass. They may be formed 
by simply bending the end of the spring over or they 
may have brass or bronze bushings. 

Spring seats or pads are the parts of the axles to 
which the springs fasten. 

Spring shackles, short pieces with a bolt hole in 
each end, used for fastening the spring parts together 
or for swinging the ends of the spring from the frame 
or brackets. 

Front springs are usually semi-elliptic, full-elliptic, 
or three-quarter-elliptic. 

Rear springs are usually three-quarter-elliptic, semi- 
elliptic, full-elliptic, seven-eighth-elliptic, cantilever or 
quarter-elliptic, this being the order in which they 
rank as to number used. 

Coil springs are sometimes used to assist the leaf 
springs. 

Auxiliary springs are springs mounted in such a 


Section 1 

MOTOR CAR PARTS 165 

way that a heavy load brings the frame near enough 
the axles so that the auxiliary springs touch the axle 
or frame and come into action. 

C. Once or twice in a season the frame should be 
jacked up so that the springs are relieved of their load, 
the leaves pried apart with a screwdriver or a special 
tool bought for the purpose, and a paste made from 
powdered graphite and oil smeared between the spring 
leaves. 

In replacing springs on the axle or brackets with 
the use of spring clips place a piece of heavy canvas 
or duck which has been soaked in white lead and oil 
between the spring and the part it rests on. 

Springs should be examined regularly to discover 
any broken leaves as it is cheaper to replace one leaf 
than to wait for the whole spring to break. 

T. Broken springs should be replaced with new ones, 
new leaves being enough if they are not all broken. 

In ordering new springs several dimensions must 
be given. These dimensions should be given as the 
spring would appear under load, and the load on the 
spring at the time the dimensions were taken should 
be mentioned in the letter. The dimensions may be 
given without load and the load that the spring will 
have to carry should be mentioned together with the 
amount that the spring should settle under that load. 

(1) The length of the spring is the distance from 
the center of one eye to the center of the other eye. 

(2) The width of the spring is the width of the leaves. 

(3) The thickness is the thickness of the whole spring 
at its thickest point. (4) The drop is the distance 
from a straight line drawn between the centers of the 
eyes and the seat or pad on which the springs rest. In 


Section 1 
166 


MOTOR CAR PARTS 


some cases the drop is given from the straight line to 
the top of the spring, although this is not the correct 
way to measure. (5) The number of leaves, the thick¬ 
ness of the leaves and the thickness of each should be 
given. (6) At the central part of each spring is a 
small bolt or else a raised nib for locating the axle and 
which sinks into a hole in the axle and prevents the 
spring moving out of place. This nib is not usually in 
the center of the spring. Its distance from the center 
of the spring is called the offset. (7) It should also be 
specified whether the eyes turn up or down at the. front 
and rear end. (8) The diameter of the bolt holes 
should be given and whether they are to be plain or 
bushed. 

Broken spring leaves may be welded by a skillful 
blacksmith. 

Rattling from around the springs is caused by the 
bolts not holding the shackles against the sides of the 
spring eye. This may be corrected by tightening 
the bolts or by inserting thin washers or shims. The 
bolts may also be loose in the eyes, requiring new bolts 
or bushings. The bolts may also be loose in the 
shackle holes, requiring new shackles or bolts or both. 
Sometimes the spring seats are clamped around the 
rear axle housing in two parts. This makes a plain 
bearing, and should play develop there, it must be 
treated the same as any other plain bearing. 

Squeaks may come from lack of grease in the spring 
bolt oilers or grease cups, from lack of grease in the 
rear axle spring seats or it may be between the leaves 
from lack of graphite paste mentioned above. 


STEERING GEAR. 


D. The steering gear of a car is composed of a hand 
wheel for the driver; a steering column; the steering 
gear proper, composed of gears, racks, worms or other 
devices for giving a reduction in motion and an in¬ 
crease in power and at the same time changing the 
rotary motion of the wheel and column to a back and 



WORM AND SECTOR STEERING GEAR. 

Showing spring type of ball and socket joint on end of drag link. 

forth motion of the steering drop arm which is fastened 
to the steering gear proper. To this drop arm is 
fastened a rod having ball and socket joints or uni¬ 
versal joints at each end. This rod is called the drag 
link when it crosses from one side of the car to the 
other or a fore and aft rod when it runs straight for¬ 
ward to the axle. 


167 







Se.ction 1 
168 


MOTOR CAR PARTS 


This drag link or fore and aft rod fastens to the 
steering knuckle arm and this arm is fastened to or 
made in one piece with the steering knuckle, which is 
the piece fastened into the end of the axle and which 
turns with the wheel. The knuckle carries the wheel 
spindle and also another arm which carries the tie rod 
arm. This arm is fastened to one end of a rod that runs 
parallel with the axle from side to side, the other end 
of the tie rod being fastened to the tie rod arm on the 
other knuckle. 

The steering gear proper is usually composed of a 
worm carried on the end of the column and mounted 
on bearings above and below. Meshing with the worm 
is a worm gear and this worm gear is carried on a 
shaft which is mounted in bearings in the gear case. 
One end of this shaft carries the steering drop arm. 

This gearing may also be composed of a worm with 
a sliding nut. The turning of the worm raises and 
lowers the nut on the threads and this nut moves the 
drop arm. 

Another form is composed of a worm having two 
threads, one cut left handed and the other right 
handed. Enclosing this worm are two half nuts, one 
having a left hand and the other a right hand thread. As 
the worm is turned one-half of the nut goes up and 
the other down. They move an arm in one end of 
the case and this arm moves the drop arm. 

Steering gears are also made from a part of a large 
bevel gear which moves the drop arm, this bevel being 
turned by a small bevel pinion at the lower end of the 
column. 

Another type uses a rack for the back and forth 
motion in place of the drop arm, the rack being moved 
by a small gear on the end of the column. 


Section 1 

MOTOR CAR PARTS 169 

Still another type of gear has two worms, one with 
a thread that moves a long ways to each turn, the 
other moving a short distance, thus giving a reduc¬ 
tion in motion. 

C. Every joint of every type of steering gear from 
the hand wheel to the spindles should be kept tight 
and well lubricated. Every nut and bolt should be 
locked in place securely. 

The housing for the gear proper should have an oil 
or grease cup and this should be filled once a week. 
All pins and bearings having grease cups should re¬ 
ceive regular attention. The ends of the drag link 
or fore and aft rod should be kept packed with cup 
grease and covered with leather boots. The oil holes 
in the steering column or in the steering hand wheel 
spider should have a few drops of engine oil daily. 

A. Play in the steering parts may come from many 
causes. It may be in the steering gear proper where 
adjustment is provided. At the top or bottom of the 
case where the column comes out is usually a large 
nut locked in place. Turning this nut, after loosening 
it, will tighten or loosen the bearings at the top and 
bottom of the worm on the column. 

The shaft carrying the drop arm and its gearing is 
usually mounted in eccentric bearings that may be 
turned around after loosening a clamp. This turn¬ 
ing throws the gearing into closer mesh and removes 
some play. 

A rack and gear or bevel gear and pinion type have 
easily recognized means for causing the small gear 
to mesh tighter into the large one. 

A sliding nut has no means of adjustment except 
renewal. 


MOTOR CAR PARTS 


Section 1 

170 

A right and left hand worm and split nut may be 
adjusted by placing thin shims between the halves of 
the nut and the case, throwing the nut tighter into 
the worm. 

Play may also be found in the keys or pins that 
hold the hand wheel to the column. 

The fit of the drop arm on its shaft may not be tight 
or the nut holding it on may be loose. The clamping 
nut (when the shaft end of the drop arm is split) may 
not be drawn tight or may not have enough threads 
to allow it to draw tight. Keys or pins holding the 
drop arm to its shaft may also be loose or broken. 

The ball and socket joints at each end of the drag 
link or fore and aft rod may be loose and need to have 
the ends or plugs screwed farther in or else the parts 
may be so worn as to require renewal. 

The ends of the tie rod have pin and clevis joints in 
which the pin holes may be worn and need renewal of 
parts or bushing or the clevises may be loose where 
they screw onto the tie rod ends. 

The fit of the long steering knuckle bolts in the axle 
ends may be loose in the knuckle itself or more likely 
in the top or bottom hole in the axle end or yoke. 

The steering wheels themselves may also be loose on 
the spindles and may need the bearings adjusted. 

When the steering wheels are turned to point 
straight forward they should stand exactly parallel 
to each other. If pointing any other way they should 
not stand parallel. 

To test the wheel position turn either front wheel 
so that a point opposite the frame at the front edge of 
the rim and another point opposite the frame but at 
the rear edge of the rim are each exactly the same dis- 


MOTOR CAR PARTS 


Section 1 

171 


tance from the frame. These measurements should 
be from the inside or outside of the wood spoke or fel¬ 
loe to the frame, not from the rim or tire. 

Leaving this wheel in this position, similar measure¬ 
ments taken on the other front wheel should show 
exactly equal distances front and rear. 

In this position the distance from the center of the 
left hand front hub to the left hand back hub center 
should be just the same as from the right hand front 
hub center to the right hand rear hub center. 

If the front wheels do not show equal measurements 
on each side they may be set by lengthening or short¬ 
ening the tie rod that runs parallel with the axle either 
in front of or behind the axle. 

One end of this rod should have its clevis or yoke 
threaded onto the end of the tie rod. Remove the pin 
from this clevis and screw it on or off the tie rod so 
that the front or rear of the wheels comes closer to¬ 
gether as required, the lengthening or shortening de¬ 
pending on whether the tie rod is in front of, or behind, 
the axle. 

Front wheels out of line will cause hard steering by 
tending to run toward one side of the road and the 
tires will be rapidly worn out. 


TIRES AND RIMS. 


D. Casings are made to fit various types of rims and 
are called clincher, quick detachable or straight side. 

Clincher casings have the edges formed into a pro¬ 
jecting lip or bead that is designed to catch and hold in 
a lip turned in on the edge of the clincher rim. The 
tire must be stretched over the rim and allowed to 
drop into place. The air pressure in the tire forces the 
bead of the tire tightly into the clinch of the rim. In¬ 
asmuch as this type of tire must pass over the rim by 
stretching, it is always necessary to order “Clincher 
Casings” for solid one piece clincher rims. This type 
is made with a soft bead that will stretch. 

Quick detachable casings have the same shape and 
form of bead as the clincher, but the ;< Q. D.” casing 
bead will not stretch. Quick detachable rims are made 
in two or three pieces, the principal piece being the 
broad flat rim proper that 'is fastened to the wheel. 
The other parts are in the form of rings that carry 
the curve of the clinching lip. This ring is usually 
held on by another ring outside of it that drops into 
a groove or locks by some special means. The small 
rings are removed while the tire is slipped over the 
main part of the rim, the locking and clinch rims then 
being replaced. The air pressure in the tire holds 
the rim parts in place. This “Q. D.” rim will take 
the clincher or “Q. D.” casings. 

To avoid the cutting action of the rather sharp edge 
of the clincher rim another form has been developed 
172 


MOTOR CAR PARTS 


Section 1 

173 


which is known as the straight side tire. This type 
of tire has the sides coming straight down without 
any clinching bead. The edge or bead of this tire is 
made very strong so that it will not stretch a particle. 
This type is slid over the main part of the rim just like 
a “Q. D.” type and the rings hold it in place with the 
help of the air pressure. This type depends on the 



STANDARD FORM OF AIR VALVE FOR AUTOMOBILE TIRES. 

strength of the tire against stretching to prevent being 
blown over the rings. 

Rims are made with rings having a clinch on one 
side and straight or only slightly curved on the other 
side. These are called Universal rims. The rings on 
both sides of the rim are removable and by taking them 
off and turning them around either a clincher, “Q. D.,” 
or straight side tire may be used. 

Demountable rims are made in such a way that the 
entire metal rim and rings that carry the tire fully 






Section 1 

174 


MOTOR CAR PARTS 


pumped up may be removed from another inner rim. 
The rim that carries the tire is bolted or clamped to 
the inner rim which is fast to the wheel. 

C. To keep tires in good condition and to secure 
their full mileage the following rules should be ob¬ 
served : 



GAUGE FOR TESTING THE PRESSURE IN AUTOMOBILE TIRES. 


Keep them pumped up to the following pressures: 




Front Tires. 

Rear Tires. 

3 inch 

Tires 

55 pounds 

60 pounds 

3y 2 “ 

« 

63 “ 

70 

4 “ 

tc 

70 “ 

80 

4% “ 

u 

80 “ 

90 . “ 

5 

u 

90 “ 

100 


Do not run them rubbing the curb. 

Do not run in deep or hard ruts. 

Do not let them stand in oil or grease. 

Do not expose extra tires to light or cold unneces¬ 
sarily. 

Do not start or stop with a jerk. 

Do not run in or on the car rails. 


Do not overload above the following total weight of 
car less passengers for each tire: 


3 in. tires—350 lbs, 


31/ 2 x30 “ 

“ —450 

u 

3l/ 2 x33 “ 

“ —555 

(< 

3V 2 x34 “ 

“ —600 

u 

3y 2 x36 “ 

“ —600 

a 

4 x30 “ 

“ —550 

(( 


4 x32 in. tires—650 lbs. 
4 x34 “ “ —700 “ 

4 x36 “ “ —750 “ 

4l/ 2 x32 “ “ —700 “ 

4V 2 x34 “ “ —800 “ 

4l/ 2 x36 “ “ —900 “ 





Sectio- l 

MOTOR CAR PARTS 175 

Run slowly over rough or stony roads. 

Repair small cuts immediately. 

T. Cuts in the tread of the tire come from running 
over sharp stones, pieces of metal, crockery, glass, 
nails, etc., or from running in the car tracks. 

Stone bruises are caused by striking large obstruc¬ 
tions with more or less force, such as rocks, bumps, 
curbs, etc. This breaks the fabric inside the tire but 
does not show on the outside until one or two hundred 
miles later, when the bruise causes a bad blow-out. 

Blow-outs are caused by cheap or defective tires, 
stone bruises or from not observing the rules given 
above. 

Rim cutting is caused by running the tires with too 
little pressure. 

Tread wear comes from long use, from standing in 
oil or grease, from being exposed to extreme heat or 
cold, from fast running and quick starts and stops or 
from the wheels being out of line. 

Loose treads come from having skid chains fastened 
too tight, from turning corners too fast and from 
under inflation. 

From an examination of 1,000 damaged tires the 
following percentages of causes were discovered: 


Wear and tear in use.37% 

Punctures.28% 

Too little pressure.17% 

Stone bruises and small cuts.11% 

Rusty and bent rims. 4% 

Stopping too suddenly. 2% 

Standing in oil or grease. 1% 


It can thus be seen that care would prevent more 
than one-third of the tire troubles. 

See Vulcanizing. 









TORSION ROD. 


D. This is a rod or shaft or brace that prevents the 
rear axle housing from revolving. When power is 
applied to the road wheels the tendency is for the 
wheel to stand still and for the axle housing to turn 
around. If the axle cannot turn the wheel will re¬ 
volve and the car will move. The torsion rod thus 
takes the whole strain of driving the car. It is usually 
mounted rigidly on the axle housing near the center 
and has a spring or slightly flexible joint at the other 
end where it is fastened to the frame or some part 
which is carried on the frame. 

The torsion strain is often taken on the housing 
which is around the driving shaft from the transmis¬ 
sion. This housing is then called the torsion tube. 


176 


HOTCHKISS DRIVE. 


When a motor car is in motion there is a constant 
force, known as torsion effort and thrust, which is 
working on the rear axle. The rear axle, because of the 
friction created on the road by power being delivered to 
the wheels, is constantly endeavoring to creep toward 
the front of the car. This is the thrust. Then, because 
of the rotation of the wheels and axles being counter¬ 
acted by the tendency of the wheels to stop, there is a 
constant twisting action which tends to turn the axle 
housing around. This is the torsion effort. 

The first method adopted to offset these forces was 
the use of torsion and radius rods. The radius rods 
connect the axle of the car solidly with the frame, thus 
offsetting the effort of the axle to advance under the 
frame of the car. Torsion was taken care of with 
torsion rods or torsion tubes. Torsion rods are fastened 
to the axle housing and follow the drive shaft up to a 
central point on the frame, where they are fastened, in 
order to offset the torsion or twisting effort. Torsion 
tubes are really housings for the drive shaft from the 
gearset to the rear axle. These housings are made suf¬ 
ficiently stiff to offset the torsion effort. 

All of these methods are still in use on modern motor 
cars. But a far simpler method has been devised which 
is meeting with constantly increasing favor, even in the 
higher-priced machines. This is known as the Hotch¬ 
kiss principle of drive. 

In this form of construction the rear axle is con- 

177 


MOTOR CAR PARTS 


Section 1 

178 

nected with the frame through the chassis springs only, 
making the springs perform the functions of torque and 
thrust. 

It was first argued that this form of drive would sub¬ 
ject the springs to unnecessary strains, but the objec¬ 
tion has not been sustained in practice. As a matter 
of fact it has been found that a slight yielding of the 
rear axle when starting and braking, by a certain flex- 



PRINCIPLE OF HOTCHKISS DRIVE. MAIN SPRING LEAF, WHICH 
TAKES THRUST AND TORQUE, SHOWN IN BLACK 

ure in the springs, has reduced the stress upon the 
transmission members. 

In the Hotchkiss principle of drive the springs are 
attached rigidly to the rear axle, while the front end 
of the spring is secured to the frame with a bolt large 
enough to take care of the strains. 

It can be seen that the principle is a considerable 
factor in reducing weight by eliminating torsion tubes 
or rods and radius rods. 

When a car has the Hotchkiss principle embodied one 
must be particularly careful to keep the spring clips 
which fasten the axle to the springs tight at all times. 
If this is not done the axle will soon tear itself loose 
from the springs and serious trouble is likely to result. 






TRANSMISSION. 

Between the gasoline engine and the roadwheels 
will always be found some means of changing the 
relative speed of the engine and road wheels. This 
part is called the change speed gearing and may be 
made in a number of forms. The change speed gear¬ 
ing gives several speeds forward and one reverse. 

The types of transmission or change speed gearing 
in common use are the sliding gear type, the plan¬ 
etary and the friction. Hydraulic transmissions using 
oil circulated by pumps and electric transmissions are 
also used. 

Sliding gear transmissions have several pairs of 
gears on parallel shafts arranged so that one set of 
gears may be slid along one of the shafts until they 
mesh with others, giving the desired ratio of speed, 
forward or reverse. Sliding gear transmissions are 
divided into selective (the most common of all types) 
and progressive. . Selective sliding gear transmissions 
are made in such a way that the operator may pass 
from any speed to any other speed without the neces¬ 
sity of passing through other speeds between. The 
progressive type is made in such a way that the gears 
must pass from the lowest speed to the next highest, 
then to the highest and in order to return to the low¬ 
est or to reach reverse the intermediate speeds must 
be passed through. 

The planetary transmission has sets of gears ro¬ 
tating around a central gear in such a way that hold- 


Section 1 
180 


MOTOR CAR PARTS 


ing the axles of the set of gears stationary, or holding 
an enclosing ring gear stationary, or allowing the 
whole mechanism to revolve as a unit, will give a 
low forward speed, a reverse speed or high speed, 
respectively. 

The friction transmission is made with a large driv¬ 
ing wheel fastened to the engine and turning with the 
crank shaft. Placed edgewise against this is another 
wheel. Pressing the second wl^eel. against the first 
one causes the second wheel to revolve at various 
speeds, depending on its distance from the center of 
the driving disc when they are pressed together. 

Sliding Gear. C. The gearing is enclosed in a case 
which contains the oil or grease for lubrication and 
prevents dirt from getting to the gears. If the trans¬ 
mission case is separated from the clutch and crank 
case completely so that no oil or grease can pass from 
one case to the other and if the transmission is fitted 
with ball or roller bearings a light weight transmis¬ 
sion grease should be used. A heavy grease or fibre 
grease might be used if the transmission is badly 
worn and noisy. If no light grease can be secured 
mix the heavier grease with enough cylinder oil to 
thin it. 

If the transmission case is in any way connected 
with the clutch or crank case or if it is fitted with 
plain bearings nothing but cylinder oil should be used. 

The transmission case should be filled with grease 
or oil only to the level of the lower gear shaft, no 
higher than this under any circumstances. 

The covers and joints in transmission cases should 
be carefully gasketed with shellaced gaskets and the 
bearings should have well fitting packing washers or 


Section 1 

MOTOR CAR PARTS 181 

covers so that grease or oil cannot leak out of the case 
in any way. 

By referring to the cuts of the selective sliding gear 
transmission, its action will be clearly understood. 
The left hand upper gear of the pair (C-C) is fastened 
to the left hand shaft which comes from the clutch. 
This gear drives the lower one which is always in 
mesh with it, causing the countershaft to turn when¬ 
ever the clutch is engaged with the engine running. 



SELECTIVE SLIDING GEAR TRANSMISSION. 
(Vertical or Horizontal Section.) 


The right and left hand ends of the upper shaft have 
no connection, the division coming at a point under 
the gear (C). The right hand end is keyed or splined, 
and carries the sliding gears (A) and (B). Gears (2), 
(1) and (R) are fastened tightly to the lower or 
countershaft and always turn with it, remaining in 
the positions shown. The small gear (I) meshes with 
(R) at all times, as shown by the end elevation, and 
will also mesh with (B) when (B) is moved to the 


































Section 1 
182 


MOTOR CAR PARTS 


right. (R) is not large enough to mesh with (B) 
directly. 

To secure a low forward speed the gear (B) is slid 
to the left into mesh with (1) causing the drive to 
come through (C-C) with a reduction in speed and 
from (1) to (B) with a further reduction, driving 
the right hand end of the keyed shaft which is con¬ 
nected to the rear axle. 

To secure an intermediate speed the gear (B) is re¬ 
turned to the neutral position as shown and the gear 



SELECTIVE SLIDING GEAR TRANSMISSION. 

(End Elevation.) 

(A) is slid to the right, meshing with (2) and caus¬ 
ing the drive to come through (C-C) and from (2) to 
(A), giving only the reduction between (C-C). 

To secure high speed or direct drive the gear (A) 
is slid to the left until the jaws on its face engage with 
the jaws on the gear (C), thus locking (A) and (C) 
together and causing both ends of the top shaft to 
turn together at the same speed. 

To secure reverse, the gear (B) is slid to the right, 



MOTOR CAR PARTS 


Section 1 

183 

engaging with (I) and causing the drive to come 
through the gears (C-C) and from (R) into (I) at 



EMERGENCY BRAKE HAND LEVER AND GEAR SHIFT 
HAND LEVER. 

The short arm below is operated by the brake lever, the cross shaft oper¬ 
ating the transmission gears. 

which point the direction of motion is reversed by 
inserting the idler gear (I) making one more gear in 
mesh than in the other positions. The drive passes 








Section 1 

184 


MOTOR CAR PARTS 


from (I) into (B), causing the drive or keyed shaft 
to turn slowly in a reverse direction. 

A. Gears are shifted to secure the various speeds 
by means of forks or yokes which fit into a slot or 
groove cut around the gear hub. These forks or yokes 
are moved by being fastened to rods that pass out 
through the transmission case. The position of the 
yokes on the rods is usually adjustable by screw 
threads or other means, these threads being in the 
yoke so that the rod may be screwed through it or 
else on the outer end of the rod so that the parts that 
operate the rod may be screwed on or off the outer end 
of the rod. 

In the shifting rods will be found notches and in 
the case will be holes that carry a steel ball or plunger 
and a spring that presses the ball or plunger into the 
notch on the rod. These notches are in such positions 
that when the gears are meshed in any certain pair 
or ratio they will be held in full mesh by the plunger 
or ball dropping into the notch, until forcibly changed 
to another position by moving the rod. The part car¬ 
rying the plunger or ball is not always.in the case 
itself but may be in some separate part which is at¬ 
tached to the case. The threaded parts may be any 
place between the fork itself and the hand lever 
operated by the driver. 

With the hand gear shift lever placed in position 
to give one of the speeds, the gears in the transmis¬ 
sion that produce this speed should be in full mesh, 
that is, the teeth of one gear should extend all the 
way along the teeth of the other gear so that a ruler 
laid across one gear will touch the other gear all the 
way across. If the gears are not in this position you 


MOTOR CAR PARTS 


Section 1 

185 


should change them with the adjustment mentioned 
above until they are exactly right. 

In placing the transmission in the frame it must 
be tested before bolting down to see that the center 
of the shaft going to the clutch is exactly opposite the 
center of the rear end of the crank shaft. The shaft 
coming from the rear end of the transmission should 
have its center exactly on the center line of the frame 
or in a vertical line passing through the center line 
of the frame. 

T. One of the commonest troubles of sliding gear 
transmissions is that the gears do not stay in proper 
mesh while running. 

If the gears will not stay in low, second or reverse 
speeds examine the ball or plunger and notches in 
the shifter rods described under (A). If this lock 
does not hold the rod quite tightly in place the gears 
will be forced out of mesh. 

If the gears will not stay in high speed it may be 
for the same reason given above or else because the 
clutch jaws or gear teeth that lock together to give 
high speed are worn rounding so that they have not 
a secure hold or grip between the two parts that slide 
together. The only sure remedy is new parts, although 
a latch or spring catch may be fastened to the hand 
lever that will hold this lever in the high speed posi¬ 
tion. 

In some forms of mechanism there may be difficulty 
in returning the hand gear shift lever to the neutral 
position or else it may be found impossible to pass 
from neutral into one of the speeds. 

If the hand lever moves in an H-shaped slot it may 
be found that one of the small flat springs fastened to 


Section 1 
186 


MOTOR CAR PARTS 


the short levers under the H plate does not enter the 
cross slot of the H and consequently allows the small 
levers to move out of place so far that the hand lever 
cannot catch them to make the shift. These springs 
may be loose, broken, bent or twisted. 

If there are no springs or short levers under the H 
plate the trouble will be in the parts enclosed with the 
transmission case and the case will have to be opened. 
This trouble inside the case will probably be caused by 
the small locking plungers not holding the shifter rods 
in proper position for the hand lever to move from one 
rod to another. 

In case new sliding gears have to be fitted to the 
old shafts it will often be found that the new gears will 
not slide along the shaft properly. To make them slide, 
cover the surface of the shaft with a mixture of fine 
emery powder and thin oil. Work the gear back and 
forth over the emery and oil until the gear moves freely 
enough for easy shifting. 

A noisy sliding gear transmission may be caused by 
lack of oil or grease; by the transmission case frame 
bolts being loose; by loose bearings; worn or broken 
gears or gear teeth or by bent, twisted or sprung shafts. 

Sprung shafts will give an irregular grinding noise 
and will probably cause hard gear shifting. This condi¬ 
tion may possibly be seen by looking into the transmis¬ 
sion while someone else turns the engine slowly by 
hand, but to make sure it will usually be necessary to 
remove the shafts and place them between the lathe 
centers for test. 

Planetary. D. The ordinary planetary type of 
change speed gear is made by attaching a shaft carry¬ 
ing two spur gears to the engine so that this shaft with 


MOTOR CAR PARTS 


Section 1 

187 


its gears turns with the engine. Placed around each 
of the two gears are three gears which are always in 
mesh with the shaft gears. These outer gears are in 
a ring around the inner gear and are carried on pins 
which are fastened to plates. These plates have metal 
drums around their outer edge, these drums forming a 
cylindrical case for the transmission. One set of the 



PRINCIPLE OF THE PLANETARY TRANSMISSION. 

E, Gear driven from engine; P, Pinion meshing with the engine gear and 
with the outside internal tooth gear D; D, Internal toothed gear, which, 
when held stationary, with E turning, causes the pinions P to carry R 
slowly in the same direction that E turns, giving low speed forward; R, 
Ring carrying the pinions, which, when held stationary with E turning, 
causes D to travel slowly in the opposite direction to that in which E 
turns, giving reverse speed. 


outer gears also mesh into internal teeth cut on the 
inside of their drum. 

By preventing the internal gear drum from turning, 
the shaft from the transmission moves slower in the 
same direction as the engine shaft, giving a slow speed 
forward; preventing the other drum from turning 
causes the rear shaft to turn slowly in the opposite di- 



Section 1 

188 MOTOR CAR PARTS 

rection, giving a reverse speed. High speed is secured 
by having a form of cone, plate or disc clutch at one 
end of the transmission, which causes the driven shaft 
to turn at the same speed as the engine shaft, giving 
high speed forward. 

The Ford and some other makes of planetary gearing 
have no internal gears but secure the same operation 
by having all spur gears, mounted on several tubes 
operating on the outside of a shaft, the drums being 
carried at one end and the gears at the other end of the 
tubes. 

C. When planetary transmissions are not carried in 
an oil-tight case outside of the drums, the drum should 
be filled with heavy transmission grease or cup grease 
through a hole clos.ed by a small screw plug in the end 
ofithe case or between the drums. 

When there is an outside oil-tight case this should 
be filled just deep enough to cover the lower inch or 
so of the planetary drums with cylinder oil. 

Inasmuch as a planetary transmission operates by 
having brake bands which stop the drums from turn¬ 
ing, no form of graphite or grease must ever be used in 
a planetary of any form because of the danger of its 
getting onto the drums or brakes. 

A. The bands around the drums will wear and loosen 
with use in the same way that brake bands will wear 
and loosen. There is always some means of drawing 
the bands tighter around the drums by screws and nuts 
or bolts at the ends of the bands or by adjustable 
clevises or yokes in the operating rods. There will be 
a form of screw or cam adjustment at some point be¬ 
tween the ends of the bands at the transmission and 
the pedals or levers that are operated by the driver. 


MOTOR CAR PARTS 


Section 1 

189 


When the facing is worn from the bands it may be 
replaced in the same way that brake-band facing is 
replaced. 

Some bands are made from cast iron and when these 
wear out they must be replaced with new ones. 

R. When it is desired to remove a planetary trans¬ 
mission the first thing to do is to disconnect all parts 
that operate the bands or the high speed clutch and if 
the transmission is not enclosed in a case it will be 
best to remove the bands to prevent their being jammed 
out of shape. 

The flanges or universal joints at each end of the 
transmission should then be disconnected, releasing the 
transmission from the drive shaft or chains and from 
the engine. 

If the transmission is not enclosed it may then be 
taken out, but if enclosed the case, or case cover, may 
be removed and if possible the transmission lifted out 
of the case. Oftentimes the case divides at the center 
line besides having a cover on top. It will, of course, 
be necessary to take the ease apart at the center. 

To remove the Ford planetary transmission first re¬ 
move the aluminum cover over the flywheel and trans¬ 
mission by taking out all the bolts around the center 
dividing line between the upper and lower half of the 
case. This top may then be lifted off with the pedals 
and high speed operating yoke. Next, disconnect the 
universal back of the transmission case by driving out 
the pin through the hole in the casing or else loosen the 
rear axle from the cross spring and brake rods and draw 
the axle back while the frame of the car is blocked up. 
This will draw the square end of the drive shaft out 
of the universal and leave the transmission free at the 


rear. 


Section 1 

190 MOTOR CAR PARTS 

The transmission is still bolted to the engine and the 
easiest way to release it is to remove all the bolts 
around the joint between the upper and lower halves 
of the engine crank case, remove the spark plug wires 
and take off the cylinder head, take off the rods from the 
steering column to the timer and carburetor, remove 
the radiator and lift the cylinders out with the crank 
shaft, pistons, rods, magneto, transmission and clutch, 
all in one unit. 

Now turn the engine upside down on a stand and 
take out the bolts that fasten the transmission and mag¬ 
neto magnets to the end of the crank shaft. 

T. Any planetary transmission will be more or less 
noisy in low and reverse speeds but if the transmission 
should make a great deal more noise than when new it 
may be due to wear in the bearings, pins, bushings or 
gears. The only way is to examine each moving part 
for wear and replace those that are in bad shape. 

A planetary transmission may sometimes be made 
more quiet by taking it apart and replacing some or 
all of the gears and bushings in different positions so 
that they are in different relation to each other. This 
distributes the wear. 

Should the bands touch the drums continually, or 
drag, the bands will heat badly and a great deal of 
power will be lost and noise produced. This dragging 
may be caused by too tight an adjustment; by small 
springs between the ends of the bands not holding the 
ends apart; by the operating rods, levers or yokes bind¬ 
ing; by the bands coming loose from the parts that 
carry their weight; because the bands are dirty or be¬ 
cause the bands have become bent or out of round. 
The remedy is evident in each case. 


MOTOR CAR PARTS 


Section 1 

191 


If the transmission does not hold and deliver full 
power to the road wheels in low or reverse, it is be¬ 
cause the bands do not hold tight enough. The bands 
may not be adjusted tight enough or the facing may be 
dirty or worn out or covered with grease or oil. The 
bands may have been bent out of round or they may 
be loose from their supports or the pull rods. The 
operating parts may have so much wear or play that 
they do not draw the bands tight, the adjusting bolts 
or pull rods may have stripped threads or there may 
be something under the band or between the ends that 
prevents it from clamping tight around the drum. 

Should the high speed clutch give trouble it may be 
remedied according to the type of clutch—plate, disc 
or cone. 

Friction. D. Friction transmission shafts are car¬ 
ried on extra large bearings because of the very heavy 
loads produced by the holding of the wheels in contact 
to give the necessary driving power. 

The disc driven by the engine usually has its face 
or driving side made separately from the balance of the 
wheel. This face is made from a material having good 
wearing qualities and may be bolted, screwed or riv¬ 
eted to the main body of the wheel. It should last al¬ 
most as long as the car unless badly misused by apply¬ 
ing too great pressure or by excessive slipping. 

The wheel driven by the engine disc is made with a 
grooved rim and into this groove fits a paper or fibre 
ring that provides the necessary friction when in con¬ 
tact with the first disc. This fibre or paper filler is 
bolted into the rim and may be easily and cheaply re¬ 
placed when worn out. 

C. There is a great side strain or bending load on the 


Section 1 

192 MOTOR CAR PARTS 

bearings in a friction transmission and for this reason 
the bearings on all the shafts must receive a continu¬ 
ous supply of grease or oil, attention being given each 
bearing every day the car is run. 



FRICTION CHANGE SPEED GEARING. 


If a friction transmission is allowed to remain on the 
neutral point with the engine running and the discs 
pressed together, a flat spot will be worn on the driven 
wheel. Flatness may also be caused by having the car 
stalled on a hill or in mud or sand, with the trans¬ 
mission working in low or reverse without moving the: 
car. These flat spots afterwards cause a heavy bump 
whenever the car is run. 

The hand lever and discs should not be run in any 
one position steadily, as this wears deep grooves in the 
driving disc. By using various positions this is pre¬ 
vented. Deep grooves in this disc make it difficult to 
move the driven wheel for speed changes. 

In driving a car having a friction transmission do not 



MOTOR CAR PARTS 


Section 1 

193 

place excessive pressure on the pedal or lever to make 
the disc hold. There should be just enough pressure ap¬ 
plied to make the discs drive without slipping; more 
than this wears the bearings and discs and makes the 
engine work harder and yet the car has less power and 
speed than with moderate pressure. 

The contact surfaces of the engine disc and of the 
friction wheel must be kept clean and dry at all times. 
They should also be as smooth as possible, because two 
smooth surfaces have greater friction on each other 
than two rough surfaces, as may be proven by laying 
a piece of window glass on another piece and trying 
to move one over the other. 

T. A slight looseness or play in the bearings of a 
friction transmission will do no great harm and may 
be neglected. » 

Should the friction wheel develop bumps they may 
be removed by grinding off with an emery wheel but 
a new filler is best. Grooves in the engine disc may be 
dressed off in the lathe or a new surface may be fitted 
to the body of the wheel. 

If the transmission works itself into the high speed 
position while in use, it is because either one or both of 
the friction wheels are worn to a slant or bevel or their 
bearings are loose. If the surfaces are made true and 
bearings tightened, this tendency will disappear. 


MAGNETIC TRANSMISSION. 


In place of the flywheel clutch, gearset, starting and 
lighting system and their auxiliary parts, two direct- 
current dynamo machines and a drum controller are 
substituted. One of the dynamo machines has its field 
magnet frame directly connected to the engine crank¬ 
shaft, taking the place of the ordinary flywheel. The 
armature of this machine is mounted on a large hollow 
shaft which is directly connected to the propeller shaft. 
This machine is called the clutch generator, as it acts 
both as a clutch and a generator. The second dynamo 
machine has its armature mounted on the same hollow 
shaft as the first, and its field magnets are stationary. 
It is called the motor, as it is generally used as a motor 
to help drive the propeller shaft and boost the effort 
of the engine as transmitted through the clutch gen¬ 
erator, which, like any clutch, can only transmit the 
engine effort or torque. 

The clutch generator is used as a clutch alone, on the 
high speed, when it is short-circuited upon itself, and a 
small speed difference between armature and field, or a 
small slip, is necessary to establish the current in its 
windings, which energizes it and causes it to act as a 
clutch. On the high-speed position the motor plays no 
part in the transmission of power, but is used as a 
charging generator for the storage battery, which latter 
is used for cranking the engine and for the electric 
lights. 

In the first place, all power impulses of the gas 

194 


MOTOR CAR PARTS 


Section 1 

195 


engine are eliminated, and the turning effort impressed 
on the propeller shaft is as uniform and smooth as that 
from an electric motor; in fact, it is exactly the same. 
No jars or shocks can be transmitted through the 
elastic means of transmitting the engine power, as there 
is no mechanical connection at all between the engine 
and driving shaft. 

In the second place, from the time of starting the car 
from a standstill until maximum speed is reached and 
through all the range of power required from level road 
to the worst hills, the power between the engine and 
propeller shaft is never disconnected, as is the case 
where clutch is thrown out, a gear change made and 
clutch engaged again. This is all controlled by the 
small speed difference between armature and field, or a 
car to be manipulated in traffic and on winding, irregu¬ 
lar grades in a way to call forth all the power of the 
engine at just the instant and for just as long as it is 
needed. The car can be held on a grade by its engine 
power, the clutch generator slipping and holding with 
the aid of the electric motor, ready at once to go for¬ 
ward upon opening the throttle; or, by closing the 
throttle slightly, the car can be allowed to back, then 
hold, then forward again, and then up to the maximum 
speed the grade allows — all without disconnecting the 
power of the engine from the driving shaft. 

On all other power control positions but the high, 
the motor helps turn the propeller shaft, by taking cur¬ 
rent from the clutch generator in the circuit in which it 
is included. At these times the slip in the clutch gen¬ 
erator is greater than needed to energize it as a clutch, 
and the additional slip produces the current required 

14 


Section 1 

196 


MOTOR CAR PARTS 




FIG. 1—CURRENT ACTION IN CHARGING POSITION. OWEN 
MAGNETIC TRANSMISSION 



FIG. 2—CURRENT ACTION WHEN STARTING ENGINE. OWEN 
MAGNETIC TRANSMISSION 




FIG. 3—CURRENT ACTION IN NEUTRAL SETTING AND APPLICA 
TION OF ELECTRICAL BRAKE. OWEN MAGNETIC 
TRANSMISSION 

















































































































































MOTOR CAR PARTS 


Section 1 

197 




FIG. 4—FIRST SPEED POSITION CORRESPONDING TO LOW SPEED 
OF SLIDING GEAR TRANSMISSION. OWEN 
MAGNETIC TRANSMISSION 




FIG. 6—THIRD SPEED POSITION. OWEN MAGNETIC TRANS¬ 
MISSION 























































































































































































MOTOR CAR PARTS 


Section 1 

198 

for the motor, which it utilizes for giving additional 
turning effort to the propeller shaft. 

The different gradations of speed and torque are 
controlled by the relative strength of the generator and 
motor fields. The weaker the generator field compared 
to the motor field, the greater the slip and the more 



FIG. 7—SIXTH POSITION. HERE THE GENERATOR SHORT CIR¬ 
CUITS THE MOTOR AND IS MADE INTO A GENERATOR 
BY MEANS OF SHUNT FIELD AND IS 
CHARGING BATTERY 


electrical energy goes to the motor for producing 
greater torque. 

Besides the positions of power control, there is a 
neutral position in which the clutching effect is cut out, 
but the motor is so connected through a resistance as to 
act as an electric brake, in which case it becomes a gen¬ 
erator, taking power to drive it, and so braking the car. 
This brake is most effective when the speed is highest 
and is ineffective below fifteen miles per hour; it will 
hold the car on any mountain grade to twenty miles per 
hour without wear of any parts and can be applied with 
the car going sixty miles per hour. It cannot hold the 
wheels, and there is little danger of skidding, as the 






























































MOTOR CAR PARTS 


Section 1 

199 


braking effort disappears at speeds below fifteen miles 
per hour. 

Aside from the simplicity of the system and the fact 
that it displaces complicated and objectionable parts of 
the prevailing type of motor car, there are features that 
appeal to those that drive and ride in a car. 

From a standstill with the engine idling, the car can 
be smoothly and rapidly brought up to the speed of 
traffic in cities, twenty to twenty-five miles per hour, 
without a jar or shock. Acceleration is so smooth as 
to seem less rapid than it really is, and it is ac¬ 
complished without any previous speeding-up of engine 
before dropping-in of the clutch and gear changes made 
at high speed, as is the case when a rapid get-away is 
made in a geared-transmission car. 

Another feature is the coasting of the car upon clos¬ 
ing the throttle, the principle of operation of the clutch 
generator being that it will only clutch when the engine 
is running faster than the driving shaft, so that upon 
releasing the accelerator the car coasts or drifts per¬ 
fectly free, with the engine idling, 


TWO-CYCLE ENGINE. 


Two-Port. D. The two-cycle or two-stroke cycle 
engine performs the operations of inlet or suction, com¬ 
pression, explosion and exhaust in one revolution of 
the crank shaft in place of in two revolutions, as in the 
four-cycle engine. 

The two-cycle engine has no mechanically operated 
valves or valve operating parts, the only moving parts 
of the engine being the piston, connecting rod, crank 
shaft and a suction-operated valve. 

The fresh gas is compressed in the crank case until it 
has pressure enough to enter the cylinder at the end 
of the power stroke when the piston is at the bottom of 
its travel. The piston then makes its up stroke, com¬ 
pressing the gas further in the cylinder, until, at the 
upper end of the stroke, the gas is fired by the spark. 
The piston then goes down, and when near the end of 
the power stroke, the burned gas is allowed to escape. 
Immediately afterward, before the piston starts up, 
more fresh gas enters from the crank case while under 
pressure. 

The cylinder is entirely closed at its upper end, hav¬ 
ing no openings as has the four-cycle engine. The 
crank case is made gas tight and the carburetor opens 
into the crank case in place of into the cylinder. Be¬ 
tween the carburetor and the crank case is an auto¬ 
matic check valve which can open freely to allow gas 
to pass from the carburetor to the crank case, but 
should the gas attempt to return to the carburetor, this 
200 


MOTOR CAR PARTS 


Section 1 
201 


valve seats and prevents the return of the gas. The 
valve is held on its seat by a light coil spring and is 
sucked open when the piston goes up into the cylinder. 

Let us consider that the piston is at the bottom of its 
stroke or nearest the crank case and that it is caused 
to go up by the turning of the crank shaft. 



TWO PORT, TWO CYCLE ENGINE. 

x, Piston at top of stroke, ready to fire in cylinder and compress gas in 
the crank case; 2, End of the firing stroke with gas passing out exhaust port; 
3, Lower end of piston travel, admitting compressed gas to cylinder. 

As the piston goes up the space in the crank case 
below the piston gets larger and to fill this space the 
carburetor check valve opens and a charge of fresh gas 
comes from the carburetor, filling the crank case. 

When the piston reaches the top of its stroke there is 
no more suction in the crank case and the valve spring 
closes the valve. The piston then starts down and as 
the gas cannot escape from the crank case it is com¬ 
pressed. When the piston reaches a point almost at 
the lower end of its stroke the top of the piston passes 
below and uncovers a hole or port in the cylinder wall. 













Section 1 
202 


MOTOR CAR PARTS 


This hole connects to the crank case by a pipe called 
a by-pass or transfer pipe. The gas being in the crank 
case under pressure now rushes through this by-pass 
and through the hole into the cylinder, filling the cylin¬ 
der with fresh gas. 

As the piston starts up it covers the hole leading into 
the crank case and as the gas cannot escape it is com¬ 
pressed. The upward movement of the piston also 
draws more fresh gas into the crank case. 

At the top of the stroke the gas is fired the same 
as in a four-cycle engine and the expanding gas forces 
the piston down on the power stroke. At the same time 
the gas drawn into the crank case is being compressed 
by this downward movement of the piston. When the 
piston has completed about five-sixths of the power 
stroke (but before the hole leading into the crank case 
is uncovered), the top of the piston passes below and 
uncovers another hole in the other side of the cylinder 
wall, this hole being a little ways above the inlet by¬ 
pass port. This second hole or port connects with the 
exhaust piping and the burned gas immediately rushes 
out of this opening into the exhaust pipe and muffler. 

The piston continues to go down and uncovers the 
inlet port so that more fresh gas comes in from the 
crank case. This fresh gas strikes a ridge on top of 
the piston head just as it comes through the port. This 
ridge is called a deflector and is curved so that it sends 
the fresh gas toward the top of the cylinder while the 
burned gas is still going out the hole on the other side. 
This fresh gas helps to blow the rest of the exhaust 
gas out and the piston starting up closes both ports and 
compresses the charge for another power stroke. 

In the inlet by-pass there is a screen of wire mesh 


__ Section 1 

MOTOR CAR PARTS 203 

that the fresh gas must come through. It is impossible 
for fire to pass through a wire screen and this makes 
it impossible for the burning gas in the cylinder to set 
fire to the fresh gas in the crank case. This is called 
the by-pass screen. 

C. The greatest care must be used to see that there 
are no leaks into or out of the crank case or the cylin¬ 
der. This makes it important to keep the crank case 
joints, gaskets and bearings perfectly tight to avoid 
this leakage. 

It must be noted that the by-pass screen is not 
broken and has no holes or there may be an explosion 
of gas in the crank case. 

Two-cycle engines require plenty of good oil and effi¬ 
cient cooling systems as they heat much easier than 
the four-cycle. 

Inasmuch as the two-cycle engine uses the crank 
case for gas, the oiling of the engine is done by mixing 
from one pint to one quart of cylinder oil with the 
gasoline while it is in the gasoline tank. This oil then 
passes through the carburetor into the crank case and 
oils all the moving parts. 

R. The same care in removing cylinders and pistons 
and bearings is required by the two-cycle engine as is 
required for any other type, but there will be no valves 
to time nor cam shafts or valve timing gears. 

The thing to make sure of is, that every joint on the 
engine is absolutely tight when replaced. 

T. When a two-cycle motor is running without mov¬ 
ing the car it will almost always miss explosions. The 
two-cycle motor has a very limited range of speed and 
will miss explosions when running very fast or very 
slow or with the throttle nearly closed. This missing 


Section 1 

204 


MOTOR CAR PARTS 


will be impossible to avoid. If the engine pulls well 
and fires evenly while handling the car under ordinary 
conditions, it is working satisfactorily. 

Two-cycle motors require more careful carburetor 
adjustment than the four-cycle type and it will be nec¬ 
essary to adjust the carburetor more often to allow for 
weather changes. 

The same ignition and carburetor and cooling trou¬ 
bles occur as in any other type of engine. It should 
be remembered that a spark is required every time the 
piston comes to the top of its stroke. 

The only troubles that occur especially in two-cycle 
engines come from leaky joints and if these joints and 
the bearings are all tight but little trouble will develop 
and most troubles that were hard to locate will dis¬ 
appear. 

Three-Port. D. The two-port two-cycle engine is 
not really a valveless engine because an automatic 
check valve is required in the crank case to prevent gas 
passing back into the carburetor. 

The three-port engine is really valveless and differs 
from the two-port in only one way. 

The carburetor pipe does not lead directly into the 
crank case, but leads to a third port in the cylinder wall. 
This port is so far down on the cylinder wall that it is 
uncovered only when the piston is at the upper end of 
its stroke. It is uncovered by the lower edge of the 
piston passing upward. 

Inasmuch as the lower edge of the piston passes up 
and opens this port it will be seen that this port is then 
opening into the crank case. The upward movement 
of the piston causes a vacuum in the crank case and as 
soon as this inlet port is uncovered the fresh gas from 


MOTOR CAR PARTS 


Section 1 

205 


the carburetor rushes into the crank case to fill up the 
space caused by the piston going up. 

When the piston starts down, the lower edge of the 
piston immediately covers this inlet port, and the gas, 
being unable to escape until the piston gets to the bot¬ 
tom and uncovers the by-pass port, is compressed in the 
crank case in the same way as in the two-port. 

No form of two-cycle engine is ^s economical of gas¬ 
oline as a four-cycle engine. This is true for several 
reasons. 

The burned gas is not entirely cleaned out of the 
cylinder, some part of it always remaining and this 
mixes with the fresh gas and weakens its power. 

At high engine speeds the fresh gas does not have 
time to completely fill the cylinder, neither does the 
burned gas have time to properly escape. This is one 
of the reasons a two-cycle engine will not run very fast. 

At slow speeds the throttle will be nearly closed and 
the suction in the crank case is not enough to draw a 
full charge of fresh gas through this small throttle 
opening, the result being that the smaller charge oi 
fresh gas cannot give full power. 

A two-cycle engine gives more power for the num¬ 
ber of cylinders and the weight of the engine and a 
three-cylinder two-cycle engine gives as steady power 
impulses as a six-cylinder four-cycle engine. A two- 
cylinder two-cycle gives the same number of impulses 
per revolution of the crank shaft as a four-cylinder four¬ 
cycle. The two-cycle is much less complicated than 
the four-cycle in any form. 

Differential Piston. D. This type of two-cycle en¬ 
gine has a piston with the lower part larger around than 
the upper part. The cylinder has its lower part larger 


Section 1 
206 


MOTOR CAR PARTS 


than the upper. This practically makes two pistons 
and cylinders in one. The upper or regular cylinder 
burns the gas in the same way as the two and three- 
port types but the gas is compressed in the lower part 
of the cylinder by the projection on the piston, acting 
as a pump. This compressed gas then passes through 



DIFFERENTIAL PISTON, TWO CYCLE ENGINE. 

A, Small diameter firing portion; B, Large diameter compressing portion: 
V, Rotating valve. 

a rotary valve in the crank case to the upper end of the 
adjoining cylinder which is ready to compress. 

C. This type requires that all cylinder joints be tight, 
but the crank case may be neglected. It is, however, 
necessary that the long rotary valve be kept tight and 
that the by-pass screens do not leak. 














UNIVERSAL JOINT. 

D. Joints that allow power to be carried from one 
shaft to another when the shafts run at an angle to each 
other are called universals or universal joints. 

Universals are usually made with some form of clevis 
or yoke on the end of each shaft to be joined; and, with 
these clevises at right angles to each other, a square, 
cross, or solid block is inserted between the clevis ends 
and fastened with pins passing part way or all the way 
through the clevis ends and the block. 

Another form of universal joint is made by fastening 
flanges to the ends of both shafts to be joined and 
connecting these flanges with a flat piece of leather and 
bolts or with a leather belt and pins. 

C. Universal joints must be kept packed with cup 
grease and covered with leather housings or boots or 
with metal cases to exclude the dirt. The pins and 
blocks must also be renewed if badly worn or very 
loose. Leather universals should have the leather 
treated with neatsfoot or castor oil once a month. 

Metal universals require attention and greasing every 
1,000 to 2,000 miles. 

R. To take a universal apart, first remove the leather 
or metal sleeve or cover, or if it is leather type uni¬ 
versal simply unbolt the leather and slip the parts away 
from each other, allowing the leather to drop off. 

If the universal is made with metal pins the pins must 
be withdrawn. There may be two pins going straight 
through or four pins, each one sticking part way 
207 


Section 1 

208 MOTOR CAR PARTS 

through. These pins are held in place with smaller 
pins, nuts, bolts, clamps or screws and in some types 
only by the metal covering around the joint. After un¬ 
locking the pins they may be drawn or driven out one 
way or the other, allowing the joint to come apart. 


VALVES. 


D. Valves are used in the automobile engine for ad¬ 
mitting the fresh gas to the cylinders and allowing the 
burned gas to leave the cylinders at the proper time 
during the stroke of the piston. 

There are several types of valves in use for this work, 
all opening into the combustion space of the cylinder. 
Poppett valves have a flat or cup-shaped head attached 
to a long stem. The head closes a round hole in the 
cylinder so that the gas cannot escape. 

The face of the valve is the part that touches the 
metal of the cylinder or of the cage carrying the valve, 
making a tight joint. The seat is the part of the cyl¬ 
inder or of the cage carrying the valve, which the 
face comes against to make the joint. Valve lifters, 
plungers or tappets are the parts between the valve 
stems and the cams that help to open the valves. Valve 
springs are fastened to the stem to close the valve 
when not held open by the cam. Valve stem guides 
are the holes through which the stem passes. 

Sleeve valves are sections of tubing that fit between 
the piston and cylinder. There are one or two of these 
thin tubes, having holes through it near the upper end. 
These sleeves or tubes are arranged to move up and 
down by being connected to a shaft with small con¬ 
necting rods. This shaft is called an eccentric shaft 
and is driven from the crank shaft much like a cam 
shaft. As the sleeves move up and down, the holes 
come opposite each other and at the same time opposite 
209 


MOTOR CAR PARTS 


Section 1 
210 

a hole in the cylinder wall so that the gas is allowed 
to come into or leave the cylinder at the right time. 

Rotary valves are made from a long shaft having 
holes crosswise through it. This shaft is contained in 
a hole having openings leading from the sides of the 
hole to the cylinders and to the carburetor and exhaust 
manifold. The long shaft in turning brings its holes 
so that the carburetor openings or exhaust openings 
are temporarily connected to the cylinders, allowing 
the gases to be admitted or expelled at the proper 
time. The valve shaft is driven from the crank shaft 
in the same way that a cam shaft might be driven. 

R. To remove poppett valves from their cylinders 
first loosen the lower end of the valve spring.from the 
lower end of the valve stem. To do this, pry the spring 
up from the bottom so that the end of the spring is 
held above the end of the stem. To accomplish this 
you will have to remove the cap that is screwed into the 
cylinder casting above the valve, and, reaching through 
this opening, hold the head of the valve down on the 
seat with a screw driver, hammer handle or block of 
wood. 

The spring may be lifted up by a valve-spring lifter 
or in many cases with an ordinary screw driver rest¬ 
ing on some solid portion of the engine or bench. After 
the spring is pried up out of the way you can take off 
the washer, nut or key from the lower end of the stem 
and slide the valve up through its spring and out of 
the opening above the head. 

T. To grind poppett valves to a good fit— 

1. Remove all carbon or soot from the valve stem 
and see that all ridges or projections on the stem are 
filed off. 


MOTOR CAR PARTS 


Section 1 
211 


2. Examine the face and seat of the valve and if 
they are pitted or rough or have slight holes or depres¬ 
sions, they need grinding. 

3. Valves are ground by placing valve-grinding paste 
between the face and the seat and then rubbing the 
valve on the seat. The valve-grinding material is made 
into a rather thin paste and a small quantity of the 
paste is placed on the face and spread around evenly. 
As much grinding material as can be picked up on the 
tip of a pocket-knife blade is sufficient. 

4. Now take a cloth (not a piece of waste) and tie a 
string or piece of wire to the cloth and stuff it into 
the opening from the valve pocket into the cylinder 
proper. This prevents the grinding compound from en¬ 
tering the cylinder. 

5. On the top of the valve head there is usually a 
slot or holes that take the end of a screwdriver or 
forked valve-grinding tool. If there are no holes or 
slots on top of the valve there will be a hole through 
the lower part of the valve stem. These are used to 
turn the valve on its seat, the slot or holes being used 
with a screwdriver or special tool. A nail or small rod 
is stuck through the hole in the valve stem so that a 
hand-hold may be had on the valve. 

6. Place the valve in its place in the cylinder and 
start grinding by turning the valve about half way 
around and then back again. Do this several times, 
using but little pressure. Too much pressure forces 
the grinding paste from between the valve and seat 
and makes slow work. 

7. After making several half turns in alternate di¬ 
rections, the valves must be raised and placed back in a 
new position. In order to raise the valve from the seat 
15 


Section 1 
212 


MOTOR CAR PARTS 


you can push up from below on the valve stem, or else 
place a small light spring around the valve stem under 
the head so that the valve is held a little ways above 
the seat. When you press down in grinding, the valve 
is forced down onto the seat, but when you release the 
pressure, the valve will rise again. 

8. After grinding for a few minutes take the valve 
out and wash the face with gasoline or kerosene. If 
the face is a clean, even gray all around and has no 
marks, pits or spots, the job is finished and the valve 
should be gas-tight. 

To test the seating of the valve after grinding, place 
pencil marks at short distances around the face, then 
place the valve on its seat and turn once around with 
considerable pressure. The marks should all be rubbed 
off if the valve is tight. 

Gasoline or kerosene can be poured on top of the 
valve, which will not leak through if the seating is 
correct. 

Great care must be used that every trace of the grind¬ 
ing material is washed from the valve and from the seat 
and edge of the pocket before removing the cloth from 
the cylinder hole. 

Valve-grinding paste for starting the work may be 
made from a mixture of medium emery powder and 
kerosene or light oil or vaseline. To finish the work 
use fine emery powder and light oil or vaseline, or 
powdered glass mixed with light oil or kerosene. 

Timing Poppett Valves. There are usually mark¬ 
ings on the flywheel indicating when the inlet and ex¬ 
haust valve should open and close. 

These markings are in the form of lines cut across or 
on the edge of the rim of the flywheel. 


MOTOR CAR PARTS 


Section 1 

213 


A line should be brought underneath a pointer placed 
above or at one side of the flywheel just when the 
valve indicated by the marking is opening or closing. 
In case there is no pointer the line should be brought 
to the topmost point on the wheel. 



FOUR CYCLE ACTION. 

Top row, left to right—Exhaust, valve (at left) just closed and inlet 
ready to open. Inlet just closed, piston going up. Exhaust ready to open 
near end of firing stroke. End of exhaust stroke. 

Bottom row, left to right—Piston going down on the inlef stroke, up on 
the compression stroke, down on the power stroke, and up on th« exhaust 
stroke. 


The markings are made as follows: 
I O means inlet valve opens. 

I C means inlet valve closes. 

E O means exhaust valve opens. 

E C means exhaust valve closes. 










































































Section 1 

214 


MOTOR CAR PARTS 


T C means piston is at top center or the top of its 
stroke. 

B C means piston is at bottom center or bottom of 
its stroke. 

Written under these letters or close after them will 
be the numbers of the cylinders whose valves may be 
placed in these positions. In a four-cylinder engine 
these numbers will be 1 and 4 or else they will be 2 
and 3 for the reason that cylinders 1 and 4 are moving 
together and 2 and 3 are moving together. 

The reason that there are two numbers in place ot 
only one for the valve positions, is that the flywheel 
makes two complete turns for each cycle of operations 
(inlet, compression, power and exhaust). 

It will thus be seen that should either the inlet or 
exhaust valve be just ready to open or close on a cer¬ 
tain cylinder when the flywheel mark is under the 
pointer, turning the flywheel once will not make the 
same valve on the same cylinder ready to do the same 
thing for the reason that it takes two complete revolu¬ 
tions to bring this valve ready to perform the same 
operation again. 

However, one revolution will bring a corresponding 
valve (inlet or exhaust) into position to do the same 
thing as the first valve mentioned, but this valve will 
be on another cylinder, whichever cylinder is moving 
the same way as the first cylinder considered. 

If the engine has only one camshaft it will be suffi¬ 
cient to time only one valve on the engine, all the rest 
being timed automatically at the same time. 

If the engine has two camshafts it will be necessary 
to time one exhaust valve and one inlet valve. 

If the flywheel has markings for valve opening and 


MOTOR CAR PARTS 


Section 1 

215 


closing positions turn the flywheel until any marking 
selected (which one does not matter) is under the 
pointer or at the topmost point of the flywheel rim. 

Next, turn the camshaft in the same way that it runs 
until the valve indicated by the flywheel markings (in¬ 
let or exhaust) is just ready to open or close as directed 
by the markings and on either cylinder indicated by 
the numbers on the flywheel. 

Now mesh the gear on the camshaft with the small 
gear on the crankshaft, or mesh these gears with the 
idler gear found between the two while the flywheel 
and camshaft are in the positions given. 

If there are no markings on the flywheel the easiest 
way to set the valves very nearly correct is as follows: 

First, open the petcock on top of the cylinder or re¬ 
move the valve cap or spark plug so that you can feel 
or see the piston when it comes to the top of the stroke. 
Sometimes the flywheel will have T C marked, mean¬ 
ing that when this mark is under the pointer or upper¬ 
most on the flywheel the cylinder indicated by the num¬ 
ber has its piston at top center or the upper end of the 
stroke. If these marks are on the wheel it will not be 
necessary to see or feel the top of the piston. 

Next, bring number one piston to the top of its stroke 
and then turn the flywheel about one-half inch in the 
same way that it rotates. 

Now turn the camshaft in the same direction it runs 
until the exhaust valve of number one cylinder is just 
ready to close. 

Then mesh the timing gear on the camshaft with 
the one on the crankshaft or the intermediate gear 
while the camshaft and piston are in the positions 
given. 


Section 1 
216 


MOTOR CAR PARTS 


If there are two camshafts, set the exhaust valves 
as given above, then set the inlet valve so that it opens 
just as soon after the exhaust valve closes as you can 
set it, but do not let the exhaust and inlet valves be 
open at the same time. 

The inlet valve usually opens immediately after the 
exhaust valve closes, this point being anywhere from 
top center to fifteen degrees after top center on the 
inlet stroke with the piston going down. The inlet 
valve closes anywhere from fifteen to thirty degrees 
after bottom center with the piston coming up on the 
compression stroke. 

The exhaust valve opens from thirty to sixty de¬ 
grees before bottom center with the piston going down 
on the power stroke and closes from two to fifteen de¬ 
grees after top center when the piston has started down 
on the inlet stroke. 

On account of wear in the valve operating parts and 
cams it is not always possible to time the opening and 
closing of the valves as seems best. If this is the case 
it must be seen that the exhaust valve closes at the right 
time, this being the most important thing to look out 
for. You can then bring the other points of opening and 
closing as near right as possible by adjusting the length 
of the push rods, although this method may cause noisy 
operation or possibly insufficient valve opening. 

Push rods should be adjusted so that there is just 
room for a piece of wrapping paper to pass between 
the lower end of the valve stem and the top of the push 
rod. The less space left at this point the quieter will 
be the operation. 

Lengthening the push rod or valve stem opens the 
valve earlier and closes it later. Shortening the push 


Section 1 

MOTOR CAR PARTS 217 

rod or valve stem opens the valve later and closes it 
earlier. 

Lengthening the stem or rod holds the valve open 
longer and shortening them makes the time of opening 
shorter. 

If the engine is small and runs at high speed, adjust 

the valves as follows: 

Inlet opens later—12° to 15° after top center. 

Inlet closes later—25° to 30° after bottom center. 

Exhaust closes later—10° to 12° after top center. 

If the engine is large or runs slow, adjust as follows: 

Inlet opens earlier—5° to 10° after top center. 

Inlet closes earlier—15° to 20° after bottom center. 

Exhaust opens later—30° to 40° before bottom 
center. 

Exhaust closes earlier—0° to 5° after top center. 

Medium speed engines should have adjustments 
midway between the above. 

Nothing but actual trial will show the best valve set¬ 
ting for any engine. 

Timing, Sleeve Valves. Sleeve-valve engines, the 
best known being the Knight engine, operate on the 
ordinary four-cycle principle as far as the time of open¬ 
ing and closing of the valves is concerned. 

The cylinder is water jacketed on the outside and 
sliding inside the cylinder is the outer sleeve., Inside 
this sleeve is the inner sleeve and inside of the inner 
sleeve is an ordinary piston. 

There is an inlet hole or port through one side of the 
cylinder which communicates with the carburetor and 
an exhaust hole or port in the opposite side which opens 
into the exhaust manifold. 


MOTOR CAR PARTS 


Section 1 
218 

The upper ends of the sleeves slide up into a circu¬ 
lar cavity or groove in the head of the cylinder. This 
cavity has a cast iron ring in its walls much like a 
piston ring, which prevents leakage of gas between the 
sleeves and cylinder walls. This ring is called a “junk” 
ring. 

Pinned to the lower edge of the sleeves are short con¬ 
necting rods which operate from eccentrics on a shaft 
corresponding to the cam shaft in a poppett valve en¬ 
gine. One of these connecting rods is longer than the 
other. The long rod is fastened to the outer sleeve and 
the short rod operates the inner sleeve. 



CRANK SHAFT AND ECCENTRIC SHAFT OF SLEEVE 
VALVE ENGINE 


Figuring in the way that the eccentric shaft turns, 
the short connecting rod operating the inner sleeve is 
set about sixty degrees ahead of the position of the long 
connecting rod operating the outer sleeve. 

This makes the inner sleeve start down before the 
DUter one has reached the top of its travel and the in¬ 
ner sleeve gets to the bottom of its movement and starts 
up again before the outer sleeve reaches the bottom of 
























MOTOR CAR PARTS 


Section 1 

219 


its travel. The outer sleeve is always following but 
never catches up to the inner sleeve. 

The eccentric shaft turns at the same speed that the 
ordinary cam shaft turns, that is, at one-half the speed 



SLEEVE VALVE ENGINE. 

Beginning of inlet stroke at left, beginning of compression stroke at right. 


of the crank shaft. The eccentric shaft turns in the 
same direction that the crank shaft turns and is usually 
connected to the crank shaft by a silent chain. 

When the piston is within about fifty degrees of the 
bottom of the power stroke the exhaust port in the outer 















































Section 1 
220 


MOTOR CAR PARTS 


sleeve is opposite the exhaust hole in the cylinder wall 
and the sleeve is moving up. At the same time the 
inner sleeve is coming down and just as the port in 
this inner sleeve comes out of the cavity in the top of 
the cylinder wall it is opposite the port in the outer 
sleeve and since the port in the outer sleeve is opposite 
' the hole in the cylinder the burned gas escapes into 
the exhaust manifold. The outer sleeve has reached 
the top of its stroke and is moving downward slowly. 

The piston now starts up on ^he exhaust stroke and 
when it is about half way up the outer sleeve is mov¬ 
ing down quite fast so that its opening passes below the 
edge of the hole in the cylinder wall and cuts off the 
escape of gas just as the piston passes top center. 

When the outer sleeve moved down and cut off the 
exhaust it brought the hole in the opposite side of the 
sleeve opposite the hole in the cylinder that connects 
with the carburetor and as the inner sleeve went up 
at the same time, the inlet port of the inner sleeve 
comes opposite the port in the outer sleeve and the hole 
in the cylinder just after the exhaust opening was shut 
off and just as the piston starts down. These three 
ports now stay more or less opposite each other while 
the piston goes down, until, after the piston again starts 
up, the inner sleeve comes up and by passing above the 
edge of the hole in the cylinder and in the outer sleeve 
the inlet gas is cut off just after the piston starts up on 
the compression stroke. 

Both holes in the cylinder are now kept closed by the 
movement of the sleeves during the balance of the com¬ 
pression and the first part of the power strokes. 

To set or time the sleeves: 

Take the spark plug out of number one cylinder and 


MOTOR CAR PARTS 


Section l 
221 


stick a stiff wire or rod down through the opening until 
it touches the top of the piston. 

Turn the engine slowly by hand until the piston 
comes to the top of its stroke. 



SLEEVE VALVE ENGINE. 

Exhaust port opening near end of power stroke. 


With the piston in this position start and move the 
flywheel in the same direction it runs for about one-half 
or three-fourths of an inch. 

Leave the piston in this last position and turn the 
eccentric shaft in the same direction it runs until the 


























Section 1 
222 


MOTOR CAR PARTS 


inner sleeve and short connecting rod are at the bot¬ 
tommost point of their travel. 

The outer sleeve and long connecting rod should now 
be well down on their stroke. 

Mesh the gears or place the chain on its sprockets 
with the piston and sleeves in these positions. 

Timing, Rotary, etc. In any engine operating on the 
four-cycle principle the exhaust valve must close im¬ 
mediately after the piston has passed top center and 



ROTARY VALVE ENGINE. 


is ready to come down, from 2 to 10 degrees after 
top center being about right. 

The inlet valve must open just as soon after the ex¬ 
haust closes as is possible without having both valves 
open at the same time. 

Therefore, it is only necessary to bring the piston 
and the valves or ports into such positions that they 
comply with these conditions and then mesh the gears 
or attach the chains. This will properly time any valve. 





























VULCANIZING. 


Vulcanizing is the process of heating raw rubber 
gum to a point at which it changes its characteristics, 
becoming tough and elastic and capable of resisting 
wear. This process is used by applying heat gener¬ 
ated from burning gasoline, electric heating coils or a 
steam boiler to the raw rubber after the rubber is placed 
on the tire to be repaired. The construction of various 
vulcanizers differs materially in details and arrange¬ 
ments of parts. All types, however, have plates against 
which the tire is held with moderate pressure while the 
rubber is being vulcanized. In electric and steam vul¬ 
canizers there will be means for regulating the degree 
of heat. 

Temperature. The higher the temperature the less 
time is required, but the work will not be so good as 
with lower temperature and more time. 

Length of Time. Good vulcanizing depends on : 

1. Allowing the cement to dry a long time. 

2. Not touching the cemented surfaces with fingers. 

3. Taking your time and following directions. 

Terms Defined. Semi-cured patching stock is rub¬ 
ber that is left raw on one side and is vulcanized on the 
other. It is used for inside patches with the vulcanized 
side inside and the unvulcanized side facing the hole. 

Raw gum is unvulcanized rubber. It comes in vari¬ 
ous thicknesses and is used for filling up holes and cuts. 
It must be cleaned before using. 

223 


Section 1 

224 


MOTOR CAR PARTS 


Heat and Time. 

For ordinary work 

use the follow- 

ing combinations: 

Heat at 250°. 

.20 

minutes 

“ 


255° 

.19 

a 

u 

t( 

260° 

.17 

a 

t( 

(( 

265° 

.15 

a 

a 

tt 

270° 

.13 

a 

n 

a 

275° 

...12 

a 

<( 

a 

280° 

.10 

a 

tt 

a 

285° 

. 9 

a 


Remarks. Before applying the heating iron to the 
work cover the tube and patch with a piece of linen— 
never with paper. 

After removing the iron sprinkle chalk on the patch 
and rub with a cloth. 

Test each tire after vulcanizing by pumping up and 
placing in water. 

After testing let the tire dry. Then remove the valve 
core and let all the air out. Replace the core and tie 
the tire loosely. 

To Prepare Small Holes in Tubes— 

1st. Locate the leak. If it is a pinhole and there 
is no rubber gone from the tube, take a piece of un¬ 
vulcanized gum one-half inch in diameter and apply 
a thin coat of cement to one side and lay it aside to 
dry. 

2d. Clean the tube around the hole with gasoline 
and a cloth, or with a brush if necessary to cut down 
to the rubber. 

3d. Apply a thin coat of cement to the tube around 
the hole, covering a space as large as the patch. 

4th. After allowing the cement to dry for ten min¬ 
utes (no less) place the patch on the tube with the 










MOTOR CAR PARTS 


Section 1 

225 

two cemented surfaces together and apply the heat¬ 
ing iron. 

5th. Heat. Apply the heat for 10 to 15 minutes 
at temperatures between 250° and 275° with moderate 
pressure. 

To Prepare Large Holes In Tubes— 

1st. If the hole is large, or if some of the rubber is 
gone, you should cut away the rough edges, making 
the hole still larger and of a fairly regular shape. 

2d. Cut a piece of semi-cured patching stock the 
same shape as the hole and about one-fourth inch 
larger all around. 

3d. Clean the raw side of this piece and apply a thin 
coat of cement and lay aside to dry. 

4th. Wrap a piece of cloth around your forefinger 
and dip it into gasoline. While the cloth is wet clean 
the inside of the tube all around the hole until no 
more chalk comes off on the cloth. 

5th. Dip the brush in the cement and apply a thin 
coat of cement all around the hole on the inside of 
the tube by pushing the brush in through the open¬ 
ing. 

6th. Let the cement dry at least ten minutes, or bet¬ 
ter still fifteen minutes. 

7th. Mark the center of the patch on the raw or 
cemented side with a soft pencil and stick it through 
the hole so that the raw side, which has the cement 
on it, will face the hole. 

8th. Press the tube down onto the patch so that 
the patch extends evenly all around the edges of the 
hole. 

9th. Apply a thin coat of cement to the edges of the 
hole and let it dry ten minutes. 


Section 1 
226 


MOTOR CAR PARTS 


10th. Cut a piece of unvulcanized gum the exact size 
of the hole and fit it into the place so that the hole 
is filled with the rubber right out to the edges but 
not overlapping- the edge. Be sure that the hole is 
even full of rubber. 

Heat. Apply the heating iron at 250° to 280° for 
12 to 20 minutes. 


WHEELS. 


D. Automobile wheels are made either with wood 
or wire spokes. Wood wheels have been used since 
automobiles were introduced in their modern form 
but the very earliest cars were equipped with wire 
wheels. Wire wheels are now in favor again. 

A. Wire wheels may be straightened by tightening 
or loosening the small nuts that hold one end of the 
spoke to the rim or hub in practically the same way 
as bicycle wheels are straightened. 

If the wheels are out of line they may be set as di¬ 
rected under Steering Gear. 

R. Wheels are removed and replaced as directed 
under Axles, reference being made to the various rypes 
of axles in use. 

Wood wheels may be removed from their hubs by 
taking out the bolts that pass through the flanges of 
the hubs and the inner ends of the wheel spokes. 
The outer flange may then be pulled off and the other 
flange with the hub driven out by resting the spokes 
on some solid place with an opening through it large 
enough for the hub to drop through. The rim is 
placed around the wood felloe of the wheel while red 
hot and then quickly cooled, shrinking it in place. 
To remove the rim in the ordinary shop amounts to 
destroying the wheel for further use. 

T. Should a wood wheel become bent or dished 
from use or accident it must be taken to a wood work¬ 
ing or wheel shop where the spokes- can be properly 
reset and tightened in the felloe and hub. 

227 


Section 1 
228 


MOTOR CAR PARTS 


Should the rim or spoke become loose in the part 
it fits into the result will be a more or less loud 
squeak each time the wheel turns around. This squeak 
may be easily heard by some one standing beside it, 
when the car is slowly run past, or it may be heard 
by leaning out over the suspected wheel while the 
car is running. 

When the spokes become loose in the felloe the 
remedy is to take the wheel to a woodworking shop 
for re-setting or new spokes. 

If the inner ends of the spokes do not fit properly 
around the metal of the hub the hub flanges may pos¬ 
sibly be drawn tighter together. If the end of the 
spoke stays away from the hub this space may be 
filled up by pouring it full of melted lead or melted 
sulphur. 

While these methods may give satisfaction, their 
value is doubtful. The proper remedy is new spokes 
or a new wheel. 


WRIST PINS. 


D. The wrist pin passes through the piston from 
side to side. Inside the piston the upper end of the 
connecting rod has a bearing on the wrist pin so that 
the power delivered to the piston by the burning gas 
is transmitted to the connecting rod through the 
wrist pin. 

Wrist pins are made from steel with the surface 
hardened. 

The wrist pin may be fastened tightly into the piston 
walls and in this case the upper end of the connecting 
rod has a bearing and a slight turning motion or rock¬ 
ing motion on the wrist pin. 

In other engines the upper end of the connecting 
rod fastens or clamps tightly around the wrist pin 
and the pin then turns in and has a bearing in the 
piston wall. This is the more modern practice. The 
hole in the piston wall is then provided with a brass 
or bronze bushing or bearing, or the bearing may 
simply be the hole bored in the wall of the piston. 

As a rule, wrist pin bearings are made in one piece, 
but in some engines having the connecting rod turn 
on the wrist pin the bushing in the upper end of the 
connecting rod may be split along one side. The up¬ 
per end of the connecting rod is then formed into a 
clamp. 

A. There should be a sidewise play or movement 
of the connecting rod along the length of the wrist 
229 


Section 1 

230 


MOTOR CAR PARTS 


pin or else the wrist pin should have a slight endwise 
play in its bearings. 

If, however, the bearings have up and down play or 
looseness noticeable when pulling and pushing on the 
connecting rod this looseness must be removed. 

If the upper end of the connecting rod is a clamp, 
remove some of the washers or shims between the 
edges of the clamp and draw the bolt tighter than 
it originally was. 

Looseness in a solid bushing makes it necessary to 
replace it with a new bushing. Before doing this re¬ 
move the wrist pin and test it for perfect roundness 
at several points with the micrometer calipers. 

If the wrist pin is not perfectly round a new one 
must be secured or else the old one must be made 
round by grinding on a grinder. After a wrist pin 
has been ground a bushing must be specially made 
and fitted with, freedom of movement but without 
play. 

Should there be no bushing in the piston walls, the 
pin have its bearing in the piston wall itself, the play 
' can be remedied only by new pistons and possibly 
new pins, or you may test and make the pin per¬ 
fectly round, bore the hole in the piston wall larger 
and insert a special bushing made for the job. 

T. Should a wrist pin have movement enough 
lengthwise of the holes in the piston so that it can 
work out and touch the cylinder walls it will cut 
deep grooves in the walls, making it necessary to 
handle the job as given under Cylinders. 

R. There is always some way of locking or fasten¬ 
ing the wrist pin so that it cannot work out and touch 


MOTOR CAR PARTS 


Section 1 

231 


the cylinder wall. This may be done with clamps, 
set screws, straight or taper pins, plugs screwed in 
the ends of the pin, by an extra piston ring passing 
around outside the wrist pin ends or in some other 
noticeable way. When reassembling an engine be 
sure that the pin is securely locked in place. 


WORKING OF THE FOUR CYCLE ENGINE. 


Stroke and Revolution. When the piston moves 
from one end of the cylinder to the other end as far as 
it can travel it has made one “stroke,” that is, from 
the closed end or head of the cylinder to the open end 
is one stroke and from the open end back to the closed 
end is another stroke. 

The crank shaft and the fly wheel make one com¬ 
plete turn or one “revolution” to two strokes of the 
piston. The piston makes one out stroke and one in 
stroke while the fly wheel turns around once. 

The Inlet Stroke. When we wish to start the en¬ 
gine the first thing to do is to fill the combustion space 
with fresh gas and the more fresh gas we can get into 
this space the more power we will get from the engine. 

The crank shaft must be turned until it moves the 
piston as near to the cylinder head as it will go, then, 
the inlet valve must open. Now, by turning the crank 
shaft more the piston will be drawn to the outer end 
of the cylinder. 

The hole that was opened by the inlet valve connects 
with a pipe that leads to the carburetor (where the 
gasoline is mixed with air so that the mixture will 
burn) and as the piston moves toward the open end of 
the cylinder it will draw the cylinder full of fresh gas. 

The stroke that fills the cylinder with fresh gas is 
called the “inlet stroke” or the “suction stroke.” 

The Compression Stroke. At the end of the inlet 

232 




MOTOR CAR PARTS 


Section 1 

233 


stroke, when we have drawn all the gas into the cylin¬ 
der that it will hold the inlet valve closes. At this time 
the exhaust valve will also be closed tight. We must 
keep on turning the crank shaft and drive the piston 
back toward the cylinder head. 

Since both valves were closed the cylinder full of 
fresh gas is now packed or compressed into the com¬ 
bustion space. When the gas is compressed it be¬ 
comes very explosive and burns with great pressure. 

When the piston is as near the cylinder head as it 
will come we will set fire to the gas. The place that 
the piston is at in the cylinder when we set fire to the 
gas is the “firing point” and the stroke that compressed 
the gas is the “compression stroke.” 

The Power Stroke. The gas now burns so fast that 
it is like an explosion and the high pressure drives the 
piston back toward the open end of the cylinder. The 
piston pushes on the connecting rod, the connecting 
rod turns the crank shaft and the crank shaft turns 
the fly wheel. This stroke of the engine is the “power 
stroke” or “explosion stroke.” 

The Exhaust Stroke. At the end of the power 
stroke, when the piston has moved as far as the 
crank and connecting rod will let it go we can 
get no more work out of that stroke and the next thing 
to do is to get rid of the burned gas so that we can get 
more fresh gas into the cylinder. 

In order to get rid of the burned gas the exhaust 
valve opens and as the piston goes back into the cylin¬ 
der it pushes the old gas ahead of it and out of the 
cylinder. 

This stroke of the engine is called the “exhaust 


Section 1 

234 


MOTOR CAR PARTS 


stroke” and it ends when the piston is as near the 
cylinder head as it can get. The piston is then in a 
position to start another inlet stroke and the engine 
goes through the same work as before as long as it 
continues to run. 

The Four Cycle Engine. There is only one power 
stroke out of the four strokes of the piston, that is, the 
crank shaft and the fly wheel turn twice around, for 
one power stroke. The first full turn of the crank shaft 
makes the piston go out on the inlet stroke and back 
on the compression stroke. The next full turn of the 
crank shaft lets the piston go out on the power stroke 
and back on the exhaust stroke. 

There are four strokes of the engine, the inlet, the 
compression, the power and the exhaust and then these 
strokes are repeated over and over again as long as the 
engine runs. 

Any series of events that happens in a regular order 
and then repeats in the same order is called a “cycle.” 
The four strokes of the engine form a cycle and this 
type of engine is called a “four cycle engine.” 


SUMMARY OF THE FOUR STROKES, 


Stroke 


Revolution 


What is happening Position of valves 


Number Name 


First 

Second 



Inlet Sucks gas in 

Compression Compresses gas 
Power Turns crank shaft 

Exhaust Pushes old gas out 


Inlet valve open 


Both valves closed 
Both valves closed 
Exhaust valve open 










SECTION TWO 


How to Use, Buy or Make Materials and 
Supplies Used in Running a Car. 


Subjects in This Section Are Arranged Alphabetically Under 
the Name of the Material. 













































MATERIALS AND SUPPLIES 


Acetylene Gas Tanks. Acetylene gas for lighting 
the lamps of the car is carried in steel cylinders made 
and filled in factories. These tanks are made in 
various sizes, holding from 10 to 70 cubic feet of the 
gas. 

The Prest-O-Lite tanks are designated by letters 
according to their size. Size A holds 70 cubic feet, 
size B (the one most used) holds 40 cubic feet, size 
E (often used on small cars) holds 30 cubic feet and 
size MC (motorcycle) holds 10 cubic feet. 

The Searchlight tank corresponds in size to the 
size B. 

One of these tanks, when emptied of its gas, may 
be exchanged for a full one by paying for the gas, 
from two and one-half to six and one-quarter cents 
per cubic foot of gas, depending on the locality where 
purchased. 

As a general rule the owner throws away from one- 
fourth to one-half the total amount of gas he buys 
because of leaking hose connections at the lamps, leaky 
or broken joints in the copper or brass piping on the 
car and from not screwing the union tight at the tank. 
See Carbide. 

Alcohol. Alcohol is made by distilling various 
kinds of plants and woods, it being possible to produce 
alcohol in any part of the country and from almost 
any vegetable matter at hand. As a fuel it has ad¬ 
vantages and disadvantages. 

3 


Section 2 

4 


MATERIALS AND SUPPLIES 


Undoubtedly the time is coming when alcohol will 
be used successfully as a fuel. With the present gov- 
ernment rules concerning the sale of alcohol in any 
form, taxation is so high that its cost is prohibitive as 
a fuel, but it is only taxation which is holding the price 
of alcohol up. 

When the authorities come to realize the value of 
this product as a combustion medium the ruling will be 
so altered that a very cheap fuel will be found. It has 
been proved that alcohol can be made from practically 
any kind of rubbish or refuse. 

It seems regrettable that, because of irregular con¬ 
trol of the liquor industry, it has been found necessary 
to retard mechanical progress by classing all alcohol 
as a beverage and so taxing it, but steps are already 
under way to alter this consideration. 

Alcohol is slightly heavier than gasoline, having a 
specific gravity of about .820. Its fuel value (heat 
units) per gallon is only about 57 per cent of that of 
gasoline so that it would take at least a gallon and a 
half of alcohol to drive the car as far as a gallon of 
gasoline would drive it. For this reason, alcohol 
would have to sell for much less than gasoline to 
compete with it. 

When a carburetor is used for alcohol the flow 
through the nozzle must be almost once and a half the 
flow of gasoline under the same conditions. It is no 
more necessary to heat alcohol than it is to heat gas¬ 
oline but the compression in the engine should be 
twice as great as with gasoline, from 130 to 190 pounds 
per square inch. 


MATERIALS AND SUPPLIES 


Section 2 

5 


Any engine might be used with alcohol by applying 
means for heating the incoming air, the same as 
would be done for gasoline, fastening enough cast iron 
plates to the top of the piston to raise the compression 
to at least 150 pounds and fitting a larger carburetor or 
nozzle or opening the needle valve more. 

Alcohol is cleaner when burned and has less odor 
than gasoline. 

Grain or ethyl alcohol is the kind found in intoxi¬ 
cating liquors. 

Wood or methyl alcohol is made from wood and is 
very poisonous. 

Denatured alcohol is grain alcohol with some wood 
alcohol or other substance added to make it unfit for 
drinking purposes. 

Anti-Freeze Mixtures. See under Cooling Systems. 

Benzol Fuel. Is used in England and Europe in 
place of gasoline to a large extent. It is not produced 
or used in this country to amount to anything. It is 
made while producing coke. Benzol, like kerosene, 
develops more power from a gallon than gasoline. 

Carbide. (Calcium Carbide) Is used for making 
acetylene gas for burning in the lamps of the car. The 
carbide, purchased in small lumps, is placed in a gas 
generator so that a small stream of water can run onto 
the carbide when gas is wanted. The water and car¬ 
bide form acetylene gas which is led to the lamp burn¬ 
er through suitable tubing and connections. 

The carbide is held in a wire bottomed basket and 
the used part or ash should drop through into another 
chamber below the basket. If this lower compart- 


MATERIALS AND SUPPLIES 


Section 2 

6 

ment becomes filled with the ash the generator can 
no longer act. The whole interior of the generator 
must be kept clean and the small pipe and valve that 
allow the water to come from the upper tank to the 
wire basket must be kept open so that the water may 
have a free flow when the valve is turned on. 

The gas pipes leading to the lamps must be kept 
perfectly tight or most of the gas will be lost and the 
lamps wdll not burn properly. To test these pipe lines 
remove the end from the generator or tank and have 
an assistant hold the two lamp lines closed by squeez¬ 
ing the hose connections tight or by taking them off 
the lamps and holding the ends closed. If you can 
force air into the generator end there is a leak that 
should be repaired at once. 

The lamp burners themselves are made with two 
very small holes for the gas to come out of. These 
holes are set in arms of the burner so that the stream 
or jet of gas.coming from one strikes the jet coming 
from the other and spreads the flame into a broad 
white light. 

Should one of these small holes become clogged 
the flame from the other one will be so long that it 
will almost always strike the mirror in the back of 
the lamp or the glass in front of the burner. It will 
crack either one of them and as the glass is worth 
about thirty cents and the mirror from one to four 
dollars this should be avoided. The holes should be 
kept clean with a very small wire, not much larger 
than a bristle. These may be bought from supply 
stores as Burner Cleaners. 

The burner should be screwed snugly onto its 


Section 2 

MATERIALS AND SUPPLIES 7 

threaded pipe so that there will be no gas leak around 
the threads. The burner should be turned until the 
broad, flat part of the flames faces forward, not with 
the edge of the flame pointing forward. 

Castor Oil for Lubricating. Castor oil has been 
used a great deal in racing cars for two reasons. It is 
not dissolved by gasoline and it retains its body and 
lubricating qualities at a heat far above that at which 
petroleum mineral oils burn up or become extremely 
thin and of little lubricating value. These qualities 
apply only to absolutely pure unadulterated castor 
oil. If the oil has been mixed with other vegetable 
oils these properties disappear and the oil becomes 
dangerous to use under any conditions. Castor oil’s 
great disadvantage is its very disagreeable odor from 
the exhaust. 

Castor oil is not suited for use in circulating systems 
as it loses some of its good properties and becomes 
thick and gummy in constant use, forming a thick 
deposit of coke or carbon on the inside of the com¬ 
bustion chamber. Pure fresh castor oil lubricates even 
better at a high temperature than at comparative low 
heat. 

The purity of castor oil may be tested by placing 
one part of the oil in a clean glass and adding five 
times as much grain alcohol (90% alcohol) with both 
parts of the mixture at a temperature of 60 to 65 de¬ 
grees Fahrenheit. If there is any impurity in the cas¬ 
tor oil the mixture will be cloudy, if the oil is pure 
the mixture will be clear. 

Chalk (Talc or Soapstone). Is used by sprinkling 
it inside the outer tire or casing and onto the inner 


Section 2 
8 


MATERIALS AND SUPPLIES 


tube so that the two will not stick together, the tube 
being easily removed after long periods of running. 
It is also used by sprinkling it on the leather facing 
of clutches (cone or plate) to prevent slipping, or be¬ 
tween the parts of the clutch should they become oily 
or greasy. A very little chalk sprinkled on the leather 
of the clutch makes it take hold and work properly, 
too much makes it grab and jerk. Chalk, talc or soap¬ 
stone is usually sold in one pound cans costing ten 
or fifteen cents or it may be bought in bulk for three 
cents and up per pound, depending on the grade and 
quantity. 

Cork, Ground. Is used by mixing it with the grease 
or oil in the sliding gear transmission case or in the 
rear axle to make old and worn out gearing run more 
quietly. Only a small quantity, about a cupful, should 
be used at first as a trial and more may be added 
to produce the desired result. If the lubricant is made 
too thick so that it may cake between the gear teeth 
there is great danger of bursting the case. Ground 
cork may be bought from supply houses for about 
fifty cents per pound. It may also be obtained at 
fruit stands, although this kind is not ground fine 
enough to do the best work. 

Sawdust, called wood fibre, is also used for this 
purpose but it cakes and gums much easier than cork 
and is more dangerous to use. 

Gasoline. Gasoline is secured by distilling crude 
petroleum, the gasoline. forming from one-thirtieth 
to one-fifth of the total quantity of crude oil. During 
this same distillation there is secured naphtha, benzine, 
kerosene, lubricating oils, asphalt, etc. 

The crude oils come from Pennsylvania, Texas and 


Section 2 

MATERIALS AND SUPPLIES 9 

California. Pennsylvania oil contains from one-eighth 
to one-fifth of its volume in gasoline, Texas and Cali¬ 
fornia oils containing only about one-thirtieth. 

In using gasoline the liquid must first be turned to 
a vapor, then mixed with about five parts of air. When 
this mixture is compressed to a pressure of seventy 
pounds per square inch and exploded it delivers about 
375 pounds per square inch pressure to the top of the 
piston and causes a heat of over 3,000 degrees. 

Gasoline has a specific gravity of about .720 in the 
grades ordinary sold, this corresponding to sixty-five 
degrees Baume scale. Gasoline is graded according 
to the Baume scale, the higher the number of degrees 
Baume the lighter the gasoline is and the better fuel 
as far as easy burning and quick evaporation go. 

Good gasoline should have a Baume test of sixty- 
eight degrees, high test gasoline tests seventy-two de¬ 
grees and extra high test shows seventy-six degrees. 
The higher the Baume test the easier the engine is to 
start and the smoother it runs, but the gasoline costs 
more in the higher grades. When the Baume test is 
below sixty degrees the liquid is called naphtha, not 
gasoline. 

The evaporation of gasoline into vapor in a car¬ 
buretor lowers the heat fifty degrees Fahrenheit, this 
being the reason for heating the incoming air or the 
manifold or the mixing chamber in modern car¬ 
buretors. 

The specific gravity or Baume test of any gasoline 
may be found by the use of a gasoline hydrometer 
which may be bought of any supply house. These 
hydrometers are floated in the gasoline and the de¬ 
grees Baume shows on the scale at the level of the 
liquid on the hydrometer scale. 

17 


Section 2 
10 


MATERIALS AND SUPPLIES 


For use in the gasoline engine this fuel should be 
practically free from water. The water may be 
strained from the gasoline by fitting a chamois skin 
over the funnel and pouring the gasoline through the 
chamois. Most of the water will remain in the 
chamois skin together with any dirt that may have 
been in the liquid. 

After gasoline is used for cleaning parts the metal 
should be wiped with a clean oily cloth to prevent 
rust unless the part is immediately replaced in the 
car where it will become covered with grease or oil. 

To prevent leakage of gasoline past the screw 
threads of joints make a thick paste of litharge mixed 
with glycerine and cover the threads before screwing 
together. This paste is not affected by the gasoline. 
Any preparation of lead and oil will be washed away 
as soon as the gasoline comes in contact with it. 

Glycerine. Is used mixed with the cooling water 
or mixed with water and alcohol to prevent the water 
from freezing in cold weather. Glycerine is sold by 
the pound and may be bought from supply houses or 
drug stores. It costs about fifty cents’per pound. 
For the proportions to use see under Anti-Freeze 
Mixtures. 

Graphite. Is almost pure carbon. It acts as a very 
efficient lubricant and friction preventative when ap¬ 
plied to any sliding parts or bearings. It may be mixed 
with oil or grease or applied dry as the case requires. 

Graphite forms a very smooth, soft covering on the 
metal surfaces, becoming so smooth and bright with 
use that the surfaces look like mirrors. 

Graphite will stand extreme heat without damage 


Section 2 

MATERIALS AND SUPPLIES 11 

and will remain in place on the bearing or sliding sur¬ 
faces under practically all conditions. 

Graphite is prepared and sold in various grades 
from large flakes down to a powder so fine that it 
does not settle in water. The flake graphite is suitable 
for use in gear boxes, rear axles, universals, pipe joints, 
etc., but not in the cylinders and crank case of an 
engine having a circulating or pumped oil feed. 

Very finely divided graphite is sold under the name 
of Oildag and is used by mixing with the engine oil. 
This Oildag comes in small cans, these cans contain¬ 
ing enough for one gallon, five gallons or ten gallons 
of oil and selling for twenty-five cents, $1.00 and $2.00 
in most localities. This same type of graphite for 
mixing with grease is sold under the name of Gredag 
in cans suitable for mixing with five, ten or twenty- 
five pounds of grease. These sizes usually sell for 
$1.50, $2.75 and $5.50 respectively. 

Flake graphite is sold in cans holding from one-half 
to five pounds of the graphite. It costs about fifty 
to seventy-five cents per pound, depending on the 
quantity in the can. 

Graphite reduces the quantity of oil or grease re¬ 
quired, by filling up all the small rough places and 
making the surfaces very smooth. It also helps to 
prevent bearings seizing from lack of enough oil. 

Grease. Should be used for lubricating where the 
pressure is heavy and the speed comparatively slow. 
The tendency in modern cars is to lessen the use of 
grease and use cylinder oil in its place wherever pos¬ 
sible. 

Grease comes in all qualities, good and bad; the 
only safe guide in buying is to secure it from a com- 


Section 2 

12 MATERIALS AND SUPPLIES 

pany having a good reputation and to pay a fair price. 
Cheap grease is usually adulterated with soap or tal¬ 
low of low grade making it unfit for use around metal 
parts. 

Grease comes in all grades from very stiff, hard cup 
grease to non-fluid oil which is but little thicker than 
cylinder oil. Greases are also mixed with graphite, 
sawdust, cork and other materials to produce special 
results. 

Cup grease is the heaviest grease ordinarily used 
around the car. It is stiff enough to be cut into pieces 
that will retain their shape. Cup grease is used in all 
grease cups anywhere on the car, in universal joints 
and steering gear cases and at any point where the 
thickness of the grease is depended upon to keep it 
from leaking. Cup grease is worth from ten to twenty 
cents a pound depending on the quantity purchased. 

Transmission greases are thinner and lighter in body 
than the cup greases. They come in several grades; 
light, medium and heavy; being thin, rather thick and 
almost as thick as cup grease respectively. Trans¬ 
mission greases are used in transmission gear cases 
having annular or roller bearings, in timing gear cases 
where this case is tightly partitioned off from the 
crank case, in all other bearings that are arranged 
grease tight, such as the wheels, in the differential 
case of the rear axle and on sliding parts except in the 
engine. 

The thinner the grease used the better the lubrica¬ 
tion and the easier the work on the mechanism, but 
do not use grease .so thin that it will work out of the 
bearings to the outside of the case. 

Transmission grease costs about one-fifth more than 
cup grease. 


Section 2 

MATERIALS AND SUPPLIES 13 

Non-fluid oils are high grade greases made from min¬ 
eral oil exclusively. They come in light, medium and 
heavy grades, the lightest being thin enough to pour 
easily. Non-fluid oils cost from twenty to thirty cents 
a pound. 

Fibre grease is rather heavy transmission or cup 
grease with which has been mixed a greater or less 
quantity of finely ground wood or cork. See under 
Cork. 

Graphite grease is composed of any grade of grease 
with which is mixed flake or powdered graphite. The 
same grade of graphite grease is used as if the grease 
had no graphite. See Graphite. 

Kerosene. Attempts are being made to use kerosene 
as a fuel for motor cars. At this writing there has not 
been evolved what might be termed a perfect kerosene¬ 
burning system. In most of the present systems the 
engine is started with gasoline, and after it becomes 
warmed up a valve is turned so that kerosene is turned 
in as the fuel. 

Kerosene contains more heat units than gasoline. 
Therefore, theoretically, it will deliver more power. 
But, because of the fact that it is very hard to vaporize 
this comparatively heavy fuel and because it is equally 
hard to keep it vaporized, tests on even the most modern 
devices show that there is enough kerosene wasted to 
come very near making up for the difference in cost. 

As previously mentioned, a good grade of gasoline 
has a specific gravity of about .720, which corresponds 
to a 65-degree Baume scale test. Commercial kerosene 
has a specific gravity of .790, giving a Baume test of 
46 to 50 degrees. Inasmuch as it is proving difficult 
even to vaporize present-day gasoline properly, one can 


Section 2 

14 


MATERIALS AND SUPPLIES 


readily see that still greater difficulty is encountered 
with the much heavier kerosene. 

Kerosene is used in the shops for cleaning parts, and 
it is very effective in loosening tight nuts and bolts, and 
any parts which have become seized, such as stuck 
pistons and bearings. It is only necessary to allow the 
kerosene to remain in contact with the joint or bearing 
for several hours, when it will work its way through, 
and then the parts may be forced apart. 

A teacupful of kerosene placed in each cylinder of the 
engine at night (while the engine is still hot) and al¬ 
lowed to remain until morning prevents the formation 
of carbon to some extent. This is not good practice, 
however, unless the crankcase oil is drained out and 
replenished after the treatment. 

Contrary to the belief of many, kerosene is not suit¬ 
able for use in the cooling system, being difficult to 
circulate and also making the fire risk much greater. 
In addition to this, it attacks and eventually ruins the 
rubber connections. 

Machine Oil. Is a very light bodied and light col¬ 
ored oil which is used for lubricating the bearings of 
magnetos, breakers and timers and electrical ma¬ 
chinery in general. It is much more suitable for this 
work than cylinder oil. 

Mica Flake. Is used in place of chalk or soapstone 
in the casings and tubes to prevent their sticking to¬ 
gether. Mica is also used like graphite, for mixing 
with grease, as it resists heat. Under some conditions 
mica is to be preferred to graphite, especially around 
some forms of electrical machinery, as it is a very good 
insulator, while graphite is a very good conductor. 


MATERIALS AND SUPPLIES Sect,on 1 J 

Neatsfoot Oil. Is used for preserving the leather 
facings in clutches in good condition. It is also used 
to prevent and cure clutches from grabbing or taking 
hold with a jerk. In refacing a clutch the leather is 
soaked in the oil as directed under Clutch, Cone, but 
in curing grabbing it can be applied by pouring it 
onto a thin piece of cardboard and then slipping the 
cardboard between the leather and metal surfaces 
while the clutch is held released. Neatsfoot oil may 
be purchased from supply stores or from harness 
shops. 

Oils, Lubricating. Cylinder oil or engine oil is used 
in all parts of the engine and in many cars in the trans¬ 
mission and rear axle as well. If the engine, clutch 
and transmission are in one unit or one case, cylinder 
oil will be used throughout the set. If the clutch and 
transmission are in one case and communicate with 
each other cylinder oil will be used in both. Any 
form of clutch running in oil requires nothing but 
oil. The greatest care must be used when other parts 
have oil passages communicating with the crank case 
that nothing but cylinder oil is used in these parts. It 
is not always apparent without careful examination 
and test, that the transmission case opens into the 
clutch and crank cases with the result that grease 
might be placed in the transmission and find its way 
into the engine, ruining the bearings and cylinder 
walls. 

Nothing but the best grades of cylinder oil should 
be considered, cheap and unknown oils usually prov¬ 
ing to be a costly experiment. Oil should be pur¬ 
chased from a reputable company, the cost in barrel 
lots being not less than twenty-four or twenty-six cents 


Section 2 
16 


MATERIALS AND SUPPLIES 


a gallon under any conditions. Tests are difficult to 
make under ordinary conditions, the best test being 
in the engine itself. This test requires at least 500 
miles’ use of the oil, at the end of which time great 
damage may have been done if the oil was of poor 
grade. 

Oil is supposed to form a thin film between the mov¬ 
ing parts so that they will not come into actual con¬ 
tact but will roll on the particles of the oil. For use 
in the automobile engine only mineral oils secured 
from crude petroleum are suitable. In racing cars 
vegetable oils are sometimes used but this has noth¬ 
ing to do with ordinary practice. See Castor Oil. 

Engine oil should stand the following tests: 

It should remain fluid when placed in crushed ice 
mixed with salt, the oil being placed in a glass bottle 
or tube and placed so it is surrounded by the freezing 
mixture. 

It should have a proper flash point. This is de¬ 
termined by having a thermometer reading up to 600 
or 700 degrees placed in the oil to be tested and the 
oil then gradually heated over a covered flame or 
stove. When the oil gets hot light a candle or match 
and hold the flame near the surface of the oil where 
the vapor can reach the flame. Watch the thermome¬ 
ter and when the vapor from the hot oil takes fire from 
the flame in small puffs and then goes out again you 
have reached the flash point of the oil as shown by 
the thermometer reading. This should not be less 
than 475 degrees Fahrenheit. While an oil must have 
a fairly high flash point, often running up to 650 de¬ 
grees, the higher the flash point the more carbon or 
soot the oil will deposit in the combustion space. 


Section 2 

MATERIALS AND SUPPLIES 17 

The oil should also have a proper fire point, this 
being found by continuing to heat the oil above the 
flash point until the oil takes fire and burns steadily. 
The temperature shown on the thermometer when 
this happens being the fire point. This temperature 
should not be less than 600 degrees Fahrenheit. 

The oil should be thin enough to flow rapidly 
through a one-fourth inch copper tube held at a slight 
slant if intended for use in water cooled engines in 
good condition. This grade would be called light oil. 

When the oil is rubbed between two smooth, flat 
metal surfaces under heavy pressure it should remain 
on both surfaces after they are separated. 

Litmus paper should be bought from a drug house 
and a piece of red and another piece of blue paper 
dipped in the oil. Neither color should change. This 
shows that the oil contains neither acids or alkalis. 
The oil may be tested for acid by soaking a piece of 
cord in the oil and wrapping it around a clean bright 
steel shaft. This should dry in the sun without dis¬ 
coloring or marking the surface of the steel in any 
way. 

When the oil is completely burned it should only 
leave a trace of ash or carbon. 

There are many grades of oil having various flash 
and fire points, cold tests, viscosities and specific gravi¬ 
ties. The grades are usually called simply light, 
medium and heavy and are bought and sold under 
these names. They all cost the same, the thickness 
having nothing to do with the cost. Light oil means, 
one that is thin and that flows very easily, medium oil 
is thicker than this and heavy oil is so thick that it 
flows slowly. These names have nothing to do with 


MATERIALS AND SUPPLIES 


Section 2 

18 

the color of the oil. The lighter the oil is in color the 
less free carbon it contains as a rule but a carbonless 
oil is an impossibility because oil is made of hydrogen 
and carbon. 

Light oil should be used for water cooled engines 
that are almost new, in very good condition or that 
run at high speeds. Light oil should be favored in 
winter because it flows easier at low temperatures. 

Heavy oil should be used in slow speed or worn 
water cooled engines, in air cooled cars and in motor¬ 
cycles. Two cylinder engines usually require heavy 
oil. There are special grades of heavy oil called air 
cooled oils for use in air cooled engine. 

Medium oil should be used in the average water 
cooled engine in good or fair shape and which runs 
at ordinary speeds. Medium oil should be favored in 
the warm weather because it does not become so thin. 

Polish, Body. Many preparations are sold which 
are claimed to make the varnished surfaces of the car 
keep their good appearance or bring this new look 
back after it has disappeared. Body polishes are no 
doubt valuable on old cars that have lost their shine 
but its value on new cars is very doubtful. In order 
to keep a car looking good it must be applied regularly 
by placing a very little on a soft clean cloth and apply¬ 
ing to the varnished surface by rubbing (only after 
the car has been washed). After applying the polish 
the surfaces should be rubbed again with another clean 
soft cloth to remove as much of the polish as possible. 
Body polish costs about seventy-five cents a quart. 

Polish, Metal. Metal polish is applied by rubbing 
it briskly and forcibly on the metal work with a small 
piece of cheese cloth well soaked in the polish. Shake 


MATERIALS AND SUPPLIES 


Section 2 

19 


the can of polish thoroughly before using and then 
pour out about half a cupful. This prevents settling 
of the polish while using, the parts that settle being 
most valuable in polishing. Let the polish dry thor¬ 
oughly on the metal and then rub off with a piece of 
clean dry cheese cloth, this cloth being washed after 
each car is polished. Good metal polish costs about 
$1.50 per gallon. It is not economical to buy smaller 
than one gallon cans. 

Radiator Leak Compounds. Many makes of com¬ 
pounds are on the market which are to be placed in 
the water when the radiator or cooling system has 
leaky spots. The compound finds its way to the hole 
and plugs it from the inside. The trouble is that there 
is great danger of its plugging any other small pas¬ 
sages it goes through. This seldom happens in prac¬ 
tice because these compounds do not swell very much 
until they strike the air. 

A very effective radiator compound consists of ordi¬ 
nary ground flax seed meal, bought for five or ten 
cents a pound at any drug store, and placed in the 
radiator. About a handful will stop a large leak 
permanently. 

Soapstone. See chalk. 

Soap, Oil. This soap is used for washing finely 
varnished and finished surfaces. Good oil soap is 
neither acid nor alkaline and therefore does no dam¬ 
age to any painted work. It looks like transparent 
grease and is of a greenish brown color. It is sold by 
the pound, coming in one, five, ten and twenty-five 
pound packages and in barrels and half barrels. In 
small quantities it sells for about twenty-five cents 
per pound. 


Section 2 
20 


MATERIALS AND SUPPLIES 


It is used by placing a small quantity, about a cup¬ 
ful, in a half a pail of boiling water and letting it dis¬ 
solve. This is then used on the car by dipping the 
sponge into the solution. 

Tire Paint. Is a composition that is claimed to 
preserve the tire by making small cuts water proof. 
It is applied with a fine brush like any paint and leaves 
the tire with a white or gray appearance. It sells for 
about $1.50 a quart. 

Top Dressing. Is for use on leather or Pantasote 
tops. It is a form of paint and enamel and is applied 
with a fine brush after washing the top thoroughly. 
It leaves a bright lustrous finish, but one that will 
crack in time like any other paint. It takes about two 
quarts to cover a top. It sells for about $1.00 per 
quart. 

Vaseline. Is a very thin grease made from crude 
petroleum. It is free from impurities and is of a very 
light body, making a very efficient lubricant for all 
bearings where light transmission grease might be 
used. It is usually used in the bearings of the mag¬ 
neto and other electrical parts, its general use being 
prevented by its cost. 

Vaseline is often used throughout the bearings, 
transmissions and rear axles of racing cars. 


SECTION THREE 


Electrical Principles Explained 




ELECTRICITY. 


Without electricity the modern gasoline automobile 
would be an impossibility. Electricity is used to fire 
the gas in the cylinders, to start the engine, to light 
the lamps and in some cars to shift the gears, operate 
the horn, furnish foot and hand warmers, cigar light¬ 
ers and all manner of necessities and conveniences. 

No one has ever been able to find exactly what 
electricity is; we can only tell about its action and 
the effects it will produce. As a general rule we may 
say that electricity will produce or cause either heat, 
light or power according to the way it is made and 
used. 

Kinds. Although all electricity is supposed to be the 
same, it seems to be in four different forms, which are 
called static electricity, magnetism, current electricity 
and radiant electricity. 

Static electricity is the form that is produced by 
rubbing one thing on another. It is the form that 
is seen in a lightning flash. Static electricity is sup¬ 
posed to be electricity that is at rest or standing still 
until it comes near enough to another body to pass 
into that body with a discharge that may pass quietly 
or may take the form of a spark through the air. 
Static electricity is of no use in automobile work and 
when it does occur we take means to get rid of it, its 
spark doing nothing but damage if allowed to pass. 

Magnetism is a form of electricity found in certain 
pieces of iron and steel and also in nickel and cobalt. 

3 


Section 3 

4 


ELECTRICITY 


The forms we will deal with are used only when in 
iron or steel. A piece of either iron or steel which 
contains magnetism is said to be magnetised and is 
a magnet. Any magnet will attract or pull another 
magnet toward it or will attract another piece of iron 
or steel. Magnetism is supposed to be electricity that 
is whirling around but that stays in the magnetised 
body while whirling. In this way it differs from static 
electricity. Magnetism is used in the automobile to 
help make electric current and also for its action in 
pulling other magnets or pieces of iron or steel toward 
the magnet. 

Current electricity is the form most valuable in our 
work. It is the kind of electricity that passes through 
wires or metal of any kind from one place to another. 
It is the kind that lights the lamps, fires the gas charge, 
starts the engine and does all the other useful things 
about an automobile. Current electricity is supposed 
to be electricity in motion in one direction and that 
will pass from one point to another in a more or less 
straight line. It does not remain in the material 
carrying it, only continuing to flow as long as supplied 
from the source where it is being produced. In this 
way it differs from both static and magnetic elec¬ 
tricity. 

Radiant electricity is not used in automobile work, 
neither does it occur in the form generally understood 
by this term. Radiant electricity is supposed to be 
vibrating, and is the kind used in wireless telegraphy. 
Its only occurrence in our work is called by another 
name, induction. 

We will deal now with current electricity, magnetism 
and then induction as applied to automobile work. 


ELECTRICITY 


Section 3 

5 

Current Flow. Anything through which the elec¬ 
tric current will flow is called a conductor. All metals 
are conductors and some other materials, such as 
water, are conductors although they are not as good 
as metals. The best conductor is silver and next to 
silver is copper. Copper lacks only a very small per¬ 
centage of being just as good a conductor as silver, 
therefore copper, being so much cheaper, is the com¬ 
monest conductor in use. Following silver and cop¬ 
per come aluminum, platinum, iron or steel and Ger¬ 
man silver in the order named, these metals all being 
used in the automobile. 

There is no such thing as a perfect conductor; they 
all have more or less resistance to the flow of the elec¬ 
tric current. This resistance to flow is determined by 
the material, increasing or decreasing as the material 
is a poor or good conductor. It is also increased when 
the conductor is smaller in size and the resistance is 
increased as the conductor becomes longer. Heat or 
cold may increase or decrease the resistance in certain 
materials. 

When a material has very great resistance, so much 
that the current does not seem to be able to flow at 
all, it is called an insulator. There is no such thing 
as a perfect insulator but some substances are so near 
to being perfect that they answer all our needs. In¬ 
sulators used in automobile work include porcelain, 
mica, glass, rubber, pitch, stone, paper, cotton, silk, 
shellac, etc. 

Current Source. Electricity for our work is pro¬ 
duced in two ways, chemical and mechanical. Chem¬ 
ical means consist of the dry cell or dry battery, me- 
18 


ELECTRICITY 


Section ‘6 

6 

chanical means consist of the magneto and the dynamo 
or generator. 

Any two materials placed in a liquid or moist bath 
of any kind form an electric cell and electric current 
will flow between the ends of the two pieces. Certain 
materials and baths are better than others, some of 
the best being used in the common dry cell. A bat¬ 
tery is made up of two or more cells, one cell cannot 
be a battery although often called a battery by those 
who do not know the difference. 

Dry cells are made from a stick of carbon sur¬ 
rounded by the bath of liquid. The liquid is soaked 
up with blotting paper and dry powders and around 
the outside is a shell of zinc. The zinc and carbon act 
on each other through the bath and will produce a 
flow of electric current between the zinc shell and 
the upper or exposed end of the carbon stick. The 
top of the cell is covered with pitch which retains the 
moisture on the inside, and around the outside of the 
zinc is a paper cover which insulates the cell from 
other pieces of metals or from other cells. At the 
upper end of the carbon is a small screw and nut for 
attaching a wire and on the upper edge of the zinc 
shell is another small screw and nut for attaching the 
other wire. 

When the liquid of the bath or the electrolyte is 
used up or if the zinc shell is used up, the battery will 
no longer give a flow of current and is no longer of 
any use. 

A lead storage cell, sometimes called an accumu¬ 
lator, is composed of two plates immersed in a bath 
or electrolyte which is contained in some form of jar 
covered at the top but not sealed tight. 


ELECTRICITY 


Section 3 

7 

The common storage battery plate is formed from 
a network of lead mixed with antimony to harden it. 
This net is called a grid and is filled with a paste made 
from red lead, litharge, water and sulphuric acid. The 
liquid around these plates is made from water and 
sulphuric acid and is called the electrolyte. The plates 
and liquid are contained in a glass, rubber or insulating 
composition jar. 

If wires carrying electric current are attached to 
the two plates and the current allowed to pass through 
the storage cell the plates and the electrolyte will 
change their composition. If these wires are then de- 



LIGHTING AND STARTING BATTERY. 

Showing the heavy terminals and top connections necessary for this work. 

tached a flow of current may be secured between the 
two plates of the cell. After this flow of current con¬ 
tinues for some time the plates and electrolyte again 
change their composition and the cell will no longer 
give a flow of current. 

The wires carrying the current may again be at¬ 
tached and the cell recharged, when it will again give 
a flow of current for some time. 

Storage cells are made with two or more plates in 
each jar, the plates being connected in two sets, about 


Section 3 
8 


ELECTRICITY 


half the plates being in each set. Each of the two 
sets has a terminal attached so that a wire may be 
fastened to the cell. 

When several cells are placed together in one box 
they are called a storage battery. This type is called 
the lead battery. 

Another type of storage battery is the Edison bat¬ 
tery which does not use lead plates but plates composed 
of and filled with compounds of nickel and iron. The 
electrolyte in place of being an acid mixture is an 
alkali, which is the opposite of an acid. Edison cells 
are charged and discharged in the same way as the 
lead battery, their advantage being that they are not 
so heavy as the lead cell. The disadvantage of an 
Edison battery is that it is not capable of discharg¬ 
ing its current flow as rapidly as the lead cell. 

The magneto, dynamo or generator all operate on 
the same principles and furnish means of changing 
mechanical power into electric current flow. 

These instruments make use of the principles of 
induction and magnetism and their action and con¬ 
struction will be explained in the sections devoted to 
ignition and electric lighting and starting systems. 

Direction of Flow. In a dry cell or storage battery 
the current is supposed to flow out from one of the 
terminals or wires, through the work and back into 
the other terminal or wire. This flow always con¬ 
tinues in the same direction and is called a direct cur¬ 
rent. 

The current generated in a dynamo, magneto or 
generator flows first out of one wire and into the 
other, then reverses and flows in at the first wire and 
out of the second. This current is then called alter- 


Section 

ELECTRICITY 

nating current. Some dynamos and generators (all 
that are used in modern lighting and starting sys¬ 
tems) are made to change the alternating current to 
a direct flow before it passes to the work. Mag¬ 
netos always give an alternating current. 

Polarity. The wire or terminal that the electric 
current flow comes out of is called the positive termi¬ 
nal or wire and the terminal or wire that it flows into 
is called the negative. 



PASSAGE OF CURRENT FROM POSITIVE TERMINAL OF DRY CELL 
THROUGH CONDUCTOR AND BACK TO THE 
NEGATIVE TERMINAL. 

Also showing how the negative wire bubbles in water. 

If you want to find which of the two wires the cur¬ 
rent is flowing out of and which one it flows into it is 
only necessary to stick the ends of the wires into some 
water which has a little salt, vinegar or other acid 
mixed with it. Keep the ends of the wires from 
touching but bring them fairly near together. The 
wire that bubbles most is the negative, the other is 
the positive. 

Connections. There are various combinations in 
use for connecting the positive and negative terminals 


CD w 












Section 3 

10 ELECTRICITY 


of cells and dynamos to each other. The same names 
are used when the same terminals of any electrical 



ft Q 

- S , 

c 

r 

c 

A — ^ 

1 

A — ^ 

> 

O 

Z 

x> 

=Q 


A ^ 

■L 

=0 3 



Jft fti 

4 



LAMP CONNECTIONS. 

I, Series; 2, Multiple; 3, Two lamps in multiple with (4) two more con¬ 
nected in series on the multiple lines. 


instruments or machines are connected in the same 
way whether the parts connected be cells, coils, electro 
magnets, dynamo parts or other parts. 


































Section 3 

ELECTRICITY 11 

A series connection is made when wires are run in 
such a way that all the current flowing in any part of 
the whole system flows through every other part and 
piece and wire, flowing from one to the next, through 
that piece and to the next one, etc. When cells or 
batteries are connected in series the positive terminal 
of one is attached to the negative terminal of the next, 
the positive of the second being attached to the nega¬ 
tive of the third, etc. When lamps are connected in 
series their terminals are connected so that the wire 
coming from the battery or dynamo goes to one termi¬ 
nal of one lamp, the other terminal of that lamp lead¬ 
ing to a terminal of the next lamp, the remaining 
terminal of the second lamp leading to the third one 
and so on until the last terminal of the last lamp is 
connected to the unused terminal of the battery or 
dynamo. 

A multiple or parallel connection is made when all 
the positive terminals of the cells, batteries, lamps, or 
dynamos are connected to each other through one wire 
or set of wires, so that the positive terminal of any 
piece is connected to the positive terminal of every 
other piece. The negative terminals are then con¬ 
nected in the same manner. 

A shunt connection is a form of multiple applied in 
a slightly different way. A wire or instrument con¬ 
nected in shunt with another piece or with a battery 
or dynamo is connected so that the current from the 
positive terminals is divided and part of it passes one 
way, through one part, while the balance of the cur¬ 
rent takes another path through another part. The 
current, after passing through the various parts con¬ 
nected in shunt is again collected and led back to the 


Section 3 

12 ELECTRICITY 

negative terminal of the battery, cell or dynamo from 
which it started. If a second wire should be con¬ 
nected between any two terminals which are already 
connected by one wire this second wire would be con¬ 
nected in shunt with the first one and any instrument 
or part carried on the second wire would be shunted 
onto the first part. A third wire and part connected 
between the same two terminals would be in shunt 
with the first two and so on for any number of con¬ 
nections made. 

A multiple-series connection is a combination of 
several parts, some of which are connected in series 
with each other and then these series sets are con¬ 
nected in multiple. The total number of parts might 
also be divided into sets with the pieces in each set 
connected in multiple and the sets connected in series. 

Current Measurement. The electric current may be 
measured according to its various qualities such as 
pressure, quantity, flow and power. 

Electricity flowing through a conductor is caused 
to flow against the resistance of the conductor by the 
pressure back of the current. This pressure may be 
great or small, much as the pressure in a pipe carry¬ 
ing w'ater may be great or small. We measure the 
water pressure in the pipe by pounds to the square 
inch but we measure the electrical pressure by volts. 
The voltage in a line has nothing whatever to do with 
the power, amount or rate of flow only when consid¬ 
ered in connection with other things. The voltage 
might be high or low while the flow might remain the 
same iust as a water pipe carrying a flow of five gallons 
per minute might have a pressure of either ten or 
100 pounds to the square inch. The voltage or pres- 


ELECTRICITY 


Section 3 

13 

sure causes the flow and power to increase providing 
all other conditions remain the same but neither power 
or flow is measured by volts. The only quality ex¬ 
pressed in volts is the pressure or strength of the cur¬ 
rent in the conductor or the force with which it is pass¬ 
ing from one place to another and with which it is 
overcoming the resistance. 

The flow of water in the pipe could be expressed 
by the number of gallons per minute. This would only 
tell the rate of flow, not the total amount of water 
that flowed or the power it might have delivered nor 
the pounds of pressure on the water in the pipe. The 
rate of flow tells how much passes a certain point in 
a certain time. If the time were long then a large 
quantity would flow; if the time were short then a 
small quantity would flow but the rate of flow would 
remain the same in either case. The rate of flow of 
electricity is measured in amperes. Amperes do not 
measure the total quantity that flowed unless we 
know the length of time that the amperage flowed. 
Amperes do not measure electrical pressure, power 
or quantity but only the rate at which the current 
passes a certain point in the same way that we would 
say the water in a river was passing under a bridge at 
the rate of so many gallons per hour or minute. 

Rate when applied to electrical measurement does 
not mean speed. Electric current always travels at 
a uniform speed, this being about 230,000 miles a 
second. 

The total quantitv of electricity is measured by 
ampere-hours. An ampere-hour is the quantity of 
current that would flow in one hour at a rate of one 
ampere. This corresponds to quarts or gallons of 


ELECTRICITY 


Section 3 

14 

water, being a definite quantity. Ten ampere-hours 
would be the quantity flowing in ten hours at a rate 
of one ampere, or it might be the quantity flowing in 
one hour at a rate of ten amperes. It might also be 
any combination of hours and amperes which would 
give ten when multiplied together. Thus, a flow of 
two amperes for five hours would equal ten ampere- 
hours. 

The power that can be delivered by an electric cur¬ 
rent is measured, by watts. Watts correspond to 
horsepower in being the power that may be delivered. 
To find the watts given by a flow of current we mul¬ 
tiply the volts by the amperes. A current of thirty 
volts pressure having a flow of five amperes would 
give thirty times five, or 150 watts. 

Seven hundred and forty-six watts of electrical 
power equal one horsepower or one watt is equal to 
one seven hundred forty-sixth of a horsepower. 

The resistance of a conductor is measured in ohms. 
One ohm resistance is a resistance that allows one 
ampere to flow if the pressure is one volt. The resist¬ 
ance of a conductor is then expressed in ohms. 

Volts, amperes and watts are measured directly by 
instruments called, voltmeters, ammeters or watt¬ 
meters. 

In order to use a voltmeter one terminal must be 
connected with the positive line or conductor or termi¬ 
nal and the other on the negative so that the pressure 
between the two may be measured. When testing 
the voltage in batteries or dynamos while they are 
delivering current it would be necessary to connect 
the voltmeter in shunt with the other parts or instru¬ 
ments. Voltmeters may be used for testing the volt- 


Section 3 

ELECTRICITY 15 

age of any battery or dynamo or the voltage in any 
conductors. 

In order to use an ammeter one of its terminals 
must be connected to the wire, battery or dynamo to 
be tested and then the wire or connection must be 
arranged so that all the current from that piece passes 
through the ammeter, out the other terminal of the 
ammeter to the connection which was on the part now 
connected to the first ammeter terminal. That is, the 
ammeter must be in series with the parts being 
tested. This usually makes if necessary to break a 
connection somewhere and insert the ammeter be¬ 
tween the ends disconnected. 

Never use an ammeter to test a storage battery un¬ 
less the battery is installed in a car having an ammeter 
as part of the equipment or until you learn now to 
connect the ammeter safely according to the instruc¬ 
tions given in the electric lighting and starting sec¬ 
tion. Never test a storage battery with an ammeter 
to see how much current it contains because the amme¬ 
ter will be damaged. 

A volt-ammeter is an instrument having a volt¬ 
meter and an ammeter in the same case. There are 
three terminals on a volt-ammeter, one being for use 
with either the voltmeter or ammeter, one of the others 
being used when voltage is to be measured and the 
remaining one being used when amperage is to be 
measured. 

Ohm’s Law. It has been discovered that the am¬ 
perage in any conductor is equal to the voltage divided 
by the resistance in ohms. That is, the amperage may 
be found if the voltage and resistance of the line are 
known. 


Section 3 

16 ELECTRICITY 

If'the" amperage and the resistance in ohms are 
known the voltage may be found by multiplying the 
amperes by the ohms. 

If the voltage and amperage are known the resist¬ 
ance may be found by dividing the volts by the 
amperes. 


MAGNETISM. 


For practical purposes there are only two things 
that can be made into magnets or that are attracted 
by magnets: they are iron and steel. No other metals 
or substances can be magnetized nor are they attracted 
or acted upon by magnets or magnetism. 

The theory of magnetism is that there are lines of 
magnetic force traveling in one direction through the 



BAR MAGNET. 

Showing path of the lines of force through the magnetic field. 

body of any piece of iron or steel that is magnetized. 
These lines start in at one end and travel straight 
through the piece to the other end. When they reach 
the far end they emerge into the surrounding air 
and by taking a curved path around the outside of the 
magnet travel back to the first end and re-enter the 

17 











ELECTRICITY 


Section 3 

18 

magnet. They then pass through as before and con¬ 
tinue circulating in this way. 

The end of the magnet from which the lines of force 
come out is called the positive pole or north pole of 
the magnet. The end that the lines of force go into 
is called the negative pole or the south pole of the 
magnet. 

The negative pole of one magnet will attract or pull 
the positive pole of another magnet to it, or the posi¬ 
tive pole will pull a negative pole to it. Two nega¬ 
tive poles have no attraction or pull for each other 
and two positive poles have no attraction for each 
other. In fact, two poles of the same kind tend to 
repel each other, that is, they try to keep away from 
each other. We say that unlike poles attract and 
like poles repel each other. 

When we wish to use the pulling power of a magnet 
we make it in a straight piece from end to end and 
call it a bar magnet. When we wish to generate 
electric current with the help of magnetism we use 
the lines of force traveling between the positive and 
negative pole of the magnet. In order to bring these 
lines into a more straight path we bend the magnet 
until it is in the shape of a capital letter U or a horse¬ 
shoe or part of a circle. This brings the ends nearer 
together so that the lines of force can take a fairly 
straight path between the poles. This type of magnet 
is called a horseshoe magnet or U shaped magnet. For 
special purposes magnets are made in the shape of a 
capital letter V and in many other forms to fit the 
place they are intended for. 

When two or more magnets are placed tight to¬ 
gether in such a way that the negative poles are to- 


ELECTRICITY 


Section 3 

19 

gether and the positive poles are together the mag¬ 
nets help each other by adding their strength together 
and the set is called a compound magnet. 

If a magnet is suspended or hung at its center so 
that it is free to swing in any direction the positive 
or north pole will turn around until it points toward 
the north and the negative or south pole will point 
toward the south. When a very small and light bar 
magnet is set on a pivot so that it can turn it is called 
a mariner's compass, or just a compass. 

It is supposed that a magnet becomes weaker from 
having the lines of force pass through the air from 
one pole to the other. It is hard for the lines of force 
to pass through the air and they slowly become 
weaker and weaker. To prevent the magnet's weaken¬ 
ing so soon a piece of iron or steel may be laid on the 
magnet from one pole to the other. The lines of 
force will then travel through the piece of iron or 
steel more than through the air. It is easier for the 
lines to travel through the iron or steel than through 
the air and the magnet does not weaken so soon. This 
piece is called a keeper or an armature of the magnet. 
When magnets are removed from a magneto or dyna¬ 
mo a keeper should always be placed across the ends. 

A piece of hardened steel when magnetized will 
remain a magnet for a long time, years in most cases. 
It is then called a permanent magnet. A permanent 
magnet becomes weaker with age and use. It be¬ 
comes weaker very fast if heated or jarred or hit in 
any way. 

A piece of iron will not retain its magnetism, al¬ 
though it may be easily magnetized. The softer the 
iron, the quicker it loses its magnetism after being 


ELECTRICITY 


Section 3 
20 

magnetized. Very soft iron remains a magnet only 
so long as the force is present that makes it a magnet 
and as soon as this magnetizing influence is removed 
the iron is no longer a magnet. 

Iron or steel may be magnetized by touching or rub¬ 
bing another magnet on the piece of iron or steel. 
They may be magnetized by having current passed 
through a coil of wire wound around the piece or they 
may be slightly magnetized by being near a powerful 
magnet or near electrical machinery. A piece of steel 
may be magnetized by holding it so it points north 
and south and tapping it with a hammer. The end 
pointing north will then be the north or positive pole 
and the end pointing south will be the negative or 
south pole. 

The easiest way to find which pole is which on a 
magnet is to have another magnet or compass, on 
which the poles are known. The poles of a compass 
are always known because the positive pole points 
north. It is then only necessary to remember that a 
pole attracted by the positive pole of the compass or 
the known magnet must be the negative pole of the 
tested magnet. 

The part of the air surrounding a magnet through 
which the magnetic lines of force travel is called the 
magnetic field. As the lines of force are thickest at 
the poles the magnetic field is strongest at or near 
the poles and weakest half way between the poles. 

If there is a keeper or an iron or steel path between 
the poles the lines of force will remain in this metal 
path for the greater part, only a comparatively small 
number passing through the surrounding air. In this 
way the magnetic field may be confined to and made 


Section 3 

ELECTRICITY 21 

to occupy a comparatively small space. Even if a 
piece of iron or steel does not touch the poles or if 
it only occupies a small part of the space between 
the poles the lines of force will collect as far as pos¬ 
sible and pass through this piece of iron or steel in 
their path from one pole to the other. 

Unless there is a path' of iron or steel between the 
poles or somewhere in the magnetic field the lines 
of force will take their natural curved paths from pole 
to pole. Lines of force easily pass through wood, 
glass, rubber, paper and all metals. There is nothing 
that prevents the passage of magnetic lines of force 
except distance. The only way to, confine the field is 
to provide an easy path for the lines of force. • 

The magnets so far considered have been permanent 
magnets of steel which hold their magnetism indefi¬ 
nitely. A form of magnet even more useful than the 
permanent magnet is called the electro magnet. An 
electro magnet is a soft piece or a number of pieces 
of iron, around which is wound a coil of insulated 
wire through which electric current may flow. The 
coil of wire is in no way connected to the iron. The 
iron must be very soft and it is called the core of 
the magnet. 

Whenever a current of electricity passes through the 
coil of insulated wire which is wound around the core 
the core becomes a magnet with a positive and nega¬ 
tive pole and all the other characteristics of a magnet. 
As soon as the current stops flowing through the coil 
or winding of the electro magnet the core is no longer 
a magnet and loses the properties of a magnet. 

The poles of an electro magnet may be found in 
the same way as if it were a permanent magnet, by 

19 


ELECTRICITY 


Section 3 
22 

testing with another magnet or compass. There is 
another way of knowing which pole is which and of 
making either end into either pole. This is according 
to which way the current passes around the magnet. 

Looking at one end of the electro magnet, start with 
the end of the winding that comes from the positive 
source of current. If this wire starts and winds around 
the core in the same direction that the hands of a 
clock move, the end of the core that you are looking 



ELECTRO-MAGNETS. 

Current passing around in clockwise direction, causing negative pole (at 
left). Current passing anti-clockwise, causing positive pole (at right). 


at is the negative pole and the other end will be the 
positive pole. If the wire passes around the core in 
a direction opposite to the way the hands of the clock 
travel or anti-clockwise, the end of the core that you 
are looking at will be the positive pole and the other 
end will be the negative. 

By connecting the wire that originally came from 
the positive terminal of the source to the other end 
of the electro magnet winding the poles will be re~ 








ELECTRICITY 


Section 3 

23 

versed, the one that was positive will then be nega¬ 
tive and the negative will be positive. 

The strength or pull of an electro magnet depends 
on the number of turns of wire in the coil and on the 
number of amperes of current passing through the coil. 
When one turn or wire around the core carries one 
ampere it is called an ampere-turn. Five turns carry¬ 
ing one ampere would give five ampere-turns. One 
turn carrying five amperes would also give five ampere- 
turns and either magnet having five ampere-turns 
would be as strong as the other one. Ten turns carry¬ 
ing one-half an ampere each would also give five am¬ 
pere-turns and the same strength. By multiplying 
the number of turns around the core by the amperes 
passing through the winding we find the strength of 
the electro magnet in ampere-turns. 

If the core of an electro magnet could be removed, 
leaving only the coil of wire, this coil would be called 
a solenoid. If the core of the electro magnet should 
then be brought to the end of the hole through the 
solenoid while current was passing through the wind¬ 
ing the core would be pulled into the hole. If the core 
is placed a little ways into the hole of the solenoid 
and the current then passed through the solenoid the 
core will be drawn into the solenoid until it is in the 
center of the coil. The strength of the pull of a solenoid 
on its plunger is measured in ampere-turns through the 
winding of the solenoid. 


INDUCTION. 


Induction is generally understood to mean the 
producing of an electric current in a conductor when 
the conductor is brought into a magnetic field and then 
removed from the field, or, when the conductor re¬ 
mains stationary and the magnetic field becomes al¬ 
ternately stronger and weaker, or, when the direction 
of the magnetic lines of force changes from one way 
to the other. 

Coils. Induction of current is produced in a coil of 
insulated wire by a magnetic field from either a perma¬ 
nent or an electro magnet. The arrangement and rela¬ 
tive location and type of the coil and magnet de¬ 
termines the type of apparatus and its suitability for 
different uses. 

There is no electrical conducting connection between 
the magnet (permanent or electro) and the wire or con¬ 
ductor in which the current is induced or produced 
by induction. 

For purposes of ignition we require a current of very 
high voltage, so high that it is capable of forcing the 
current to jump across an air gap in the cylinder and 
produce the spark that fires the charge. This requires 
a voltage of thousands and it is not practical to make 
either batteries or cells or dynamos that will produce 
such a voltage. We therefore produce a compara¬ 
tively low voltage, four to twenty-five, and by means 
of induction in a transformer coil we secure a current 
of very high voltage. 


24 


ELECTRICITY 


Section 3 

25 

If we take a core of soft iron with a winding of only 
several hundred turns of ordinary size insulated wire 
on it we have an electro magnet. By causing the cur¬ 
rent to flow in the coil and then stop flowing we make 
the iron core into a magnet and then cause it to lose 
its magnetism. 

If now we wind another coil around the outside of 



HIGH TENSION TRANSFORMER COIL. 

the first one (on this electro magnet), but make the 
second coil of thousands of turns of very fine wire, it 
will be seen that the magnetic field of the core first 
surrounds and passes through the second coil of fine 
wire and when the current ceases to flow in the coil 
of ordinary sized wire the magnetic field disappears. 
This action changes the strength of the magnetic field 
passing through the fine wire coil from the highest 







ELECTRICITY 


Section 3 

26 

power to zero each time the current flows and ceases 
to flow in the first coil around the core of the magnet. 

When the low voltage current is allowed to pass 
through the coarser winding on the first coil the mag¬ 
netic field of the core becomes strong and extends out 
through the fine wire coil. When the current ceases to 
flow in the first coil the magnetic field disappears and 
as the magnetic field leaves the fine wire coil a current 
of very high voltage is induced in the fine winding. 



PRINCIPLE OF THE INDUCTION COIL. 

This current may then be used for causing the spark 
to jump in the cylinder and fire the charge. The core 
with its two windings is called a transformer coil. 

The power or the watts of the current were not in¬ 
creased by the transformer coil. The amperage in the 
coarse wire inner coil was from one-half to one ampere 
and the voltage usually from six to eight. This would 
make three to eight watts (found by multiplying the 
amperes by the volts). 

The current coming from the fine winding, while hav- 











ELECTRICITY 


Section 3 

27 


ing a voltage of perhaps 50,000 to 100,000 volts, would 
have only one twenty-thousandth part of one ampere, 
so that the power or watts would not be increased. 

If a current of very high voltage was passed through 
the fine wire coil a current of low voltage would be re¬ 
ceived from the coarse wire coil, but the amperage 
would be greater in the low voltage current so that the 
watts would not be changed. 

A fine wire carrying the induced current raises the 
voltage and if the wire carrying the induced current is 
larger than the other one its voltage will be lower. The 
proportion of the size of the wires on the two wind¬ 
ings and the number of turns of wire determines the 
change of voltage up or down and the amount of the 
change. 

The current received from an outside source and 
sent through the winding that magnetizes the core is 
called the primary current and the current received 
from the winding in which it is induced by the chang¬ 
ing magnetic field is called the secondary current. 

In automobile work the primary current is always 
the low voltage current and the secondary current is 
always of high voltage. All wires and parts carrying 
the primary current are called primary wires and parts 
and all wires or parts carrying the secondary current 
are called secondary wires or parts. The coil receiving 
the current from the outside source is called the primary 
coil and the coil in which the current is induced is 
called the secondary coil. 

The low voltage current on an automobile is called 
low tension current and the high voltage current that 
jumps the gap to make the spark is called high tension 
current. 


Section 3 

28 ELECTRICITY 

In magnetos and dynamos the coil of wire is made 
to move in such a way that the lines of force first pass 
through the armature coil in one direction and then in 
the other direction so that the magnetic strength alter¬ 
nately rises, falls to zero and then rises again. Moving 
the coil in this way while it is in the magnetic field 
requires considerable power and in this way mechanical 
power is changed into electric current. 

In some forms of generators and magnetos the coil 
remains stationary and the lines of force are caused to 
change their direction by revolving pieces of iron be¬ 
tween the poles of the magnets. 

The action of magnetos, and dynamos will be more 
fully explained under Ignition and Electric Lighting 
and Starting Systems. 


SECTION FOUR 


ELECTRIC LIGHTING AND STARTING. 



^ • 

‘ 

t . 





































































* 








« 


















































































































































♦ 








■» 















. 




















































. 

' 







ELECTRIC LIGHTING AND STARTING. 


Electric lighting for motor cars has been used almost 
as long as the cars themselves have been on the market. 
This early electric lighting, however, made use only 
of dry cells or storage batteries as the source of cur¬ 
rent. When the current was exhausted the dry cells 
were replaced with new ones or the storage batteries 
were removed from the car and recharged from an out¬ 
side supply. 

Because of the uncertainty of the length of time that 
the lights would burn on one battery charge and the 
inconvenience of removing the battery for recharging 
or of replacing the dry cells, this proved a rather un¬ 
satisfactory method and was only used for small lamps, 
usually tail or side lamps. Installations were made for 
headlights also but the large drain on the battery made 
it necessary to carry an excessively large battery weigh¬ 
ing in many cases over one hundred pounds. 

At the time the battery systems were in use another 
form of electric current source came into use. This was 
the small dynamo or generator run from the engine by 
belts or gears, or often by friction wheels on the fly¬ 
wheel. This dynamo would give a fairly constant volt¬ 
age when the car was running above a certain speed, 
but below this speed the voltage would not be sufficient 
to light the lamps properly. These dynamos could be 
used for the headlights very easily because the head¬ 
lights were not so necessary when the car was running 
very slowly or standing. 


3 


Section 4 

4 ELECTRIC LIGHTING AND STARTING 

The next step was to fit the car with a medium size 
battery and also with a direct current dynamo which 
would keep this battery charged, the dynamo being run 
from the engine and delivering its current into the bat¬ 
tery. The lamps could then be burned from the bat¬ 
tery and the entire system would practically maintain 
itself on power received from the engine. This formed 
the basis of the modern systems of electric lighting. 

After having a battery that would remain charged 
it was a simple matter to attach an electric motor to 
the engine so that when current from the battery was 
made to revolve the electric motor the motor would 
start the engine in the same way that the driver would 
do with the hand crank. 

Since the possibilities of automatic and continuous 
battery charging were realized many electric attach¬ 
ments have been built into the newer cars, among them 
being electric gear shifters, electric brakes, electric 
horns, cigar lighters, steering wheel warmers, foot 
warmers, and almost anything that could be operated 
by electric current. Some of the modern cars have 
more electrical parts than gasoline, the electric control 
even extending to electric transmission in place of the 
ordinary gearing. 

Electric lighting and engine starting systems came 
into sudden prominence in 1911 and gained rapidly as 
standard equipment on all classes of cars during the fol¬ 
lowing years. In 1913 it was estimated that over 70 
per cent of all cars (except Fords) had this equipment 
for lighting only or for lighting and starting. In 1914 
the percentage was even greater and for 1915 it was 
hard to make a list of cars without electrical equipment 
of this kind. 


ELECTRIC LIGHTING AND STARTING*'”" 5 

There are dozens of different makes of electrical 
equipment, each maker building his outfit a little differ¬ 
ent from all others. However, a great many of these 
systems are made up from parts secured from estab¬ 
lished electrical manufacturing houses and all systems 
are made by different combinations of more or less 
standard principles so that it is possible to study them 
all by understanding these underlying principles and 
methods of building. It is of course true that this re- 



ENGINE SHOWING DYNAMO MOUNTED IN PLACE OF MAGNETO. 

quires careful study and a thorough understanding of 
electrical principles already explained as well as those 
to come. The repairman must be able to recognize or 
discover how any installation is made and controlled 
and by understanding each of the parts it will be easy 
to understand their workings in connection with each 
other. It would be useless to attempt a study of every 
different system for the reason that they would be so 
confused in the learner’s mind that the study would be 




Section 4 

6 ELECTRIC LIGHTING AND STARTING 

practically useless. Even if a man could learn the char¬ 
acteristics of every make, their design and construction 
might be more or less radically changed for next year. 
We will therefore take up each part of the system re¬ 
quired on any car and then study the various ways of 
building this part. 


PARTS REQUIRED. 


Dynamo or Generator. The dynamo is an instru¬ 
ment which changes mechanical power into electric 
current. Generator is another name for dynamo. It 
is substantially the same in its principle of operation 
as the familiar dynamos or generators which create 
current for electric lighting or for driving commercial 
electric motors, electric railways, etc. 



WAGNER GENERATOR 

B. D.—Oiling holes. X.—Ammeter wirfc plug. 

J.—Commutator cover. W.—Ammeter wire. 

The Wagner generators are made to order to fit special engine jobs. 
They are compact and of light weight. The one shown is of the silent 
chain-driven type. It will be noted that there are but two places to oil. 
These oil holes are common in practically all types of generators. A very 
light grade of oil should be used, preferably sewing-machine oil. 


The dynamo is connected to the engine by means of 
gears, chains, or possibly belts so that the dynamo runs 
and makes current whenever the engine runs. The 
dynamo usually runs at about three times the crank¬ 
shaft speed, although in some installations it runs at 

7 










Section 4 

8 ELECTRIC LIGHTING AND STARTING 

crank-shaft speed or more than three times crank-shaft 
speed. Current from the dynamo is used to charge the 
storage battery, light the lamps, and, through the 
charged battery, it starts the engine. 

Storage Battery. The storage battery receives the 
current from the dynamo that is not immediately used 
for lighting the lamps and stores this current until 
wanted for use to start the engine or for any purpose 
that requires more current than the generator is mak¬ 
ing, or, while the generator and engine are idle. The 
storage battery also serves the same purpose that an 
open tank of water would serve in a water pressure 
pumping system, that is, it maintains an even pressure 
or voltage in all parts of the system at all times. In this 
way it acts as a voltage regulator, constant voltage 
being necessary for the successful operation of the 
lamps. 

Generator Control. In order that the dynamo may 
successfully charge the battery and that the battery 
may retain its charge until wanted for proper use two 
things are necessary. 

(1) After a battery has been charged for a certain 
length of time it is said to be fully charged and should 
.not receive too,heavy an overcharge after this time. 

It is also considered necessary to charge the battery 
at a flow of only a certain number of amperes and the 
rate of charge should not exceed this number. 

To limit the charging rate or to prevent excessive 
overcharge some form of current regulation is neces¬ 
sary. This may be taken care of in the design of the 
dynamo or it may be accomplished by additional in¬ 
struments outside the dynamo. These instruments 
are called regulators and the action is called regulation. 


ELECTRIC LIGHTING AND STARTING'" 0 ” 9 

(2) As long as the generator runs at a fair rate of 
speed it will make a voltage higher than the voltage of 
the battery, and, inasmuch as the pressure at the dy¬ 
namo is greater than the pressure at the battery, cur¬ 
rent will flow from the dynamo to the battery and the 
battery will be charged. Should the dynamo speed fall 



UNITS OF A SELF CONTAINED ELECTRIC LIGHTING SYSTEM. 
Arrangement of parts on car shown above with connections for ‘‘floating 
battery on the line,” shown below. D, dynamo; B, battery. 


below the point at which it makes a voltage higher than 
the battery voltage or should the generator stop (as 
it does when the engine stops), then the battery pres¬ 
sure would be greater than the dynamo pressure and 
the current already in the battery would flow to the 
generator and the battery would be discharged. 

2U 




























!o‘ ,0 electric lighting and starting 

% 



SIMILARITY BETWEEN THE FLOW AND ACTION OF WATER 
AND ELECTRICITY. 


Upper Diagram—D, Water, pump driven from engine, its output being 
controlled by the governor (R) loosening the belt tension above certain speeds; 
C, Check valve preventing leakage of water from tank through pump when 
pump is idle; B, Water storage tank; S, Valves for admitting water to 
motors from tank; M, Water motors driven by water from tank. 

Lower Diagram—P. Dynamo taking place of the pump; G, Regulator 
acting as governor; C, Cut-out preventing current leakage through 
dynamo; A, Ammeter showing flow of current; T, Storage battery; S, 
Lighting switches; L, Electric lamps. 



































































ELECTRIC LIGHTING AND STARTING 11 


To prevent this discharge of the battery all forms of 
systems have some form of instrument or attachment 
that breaks the circuit between the battery and dynamo 
when the dynamo voltage falls below that of the bat¬ 
tery for any reason whatever. This part of the system 
is called the reverse current cut-out or simply the cut¬ 
out. 

Current Indicators. When it is desired to know the 
flow in amperes that is passing into the battery from 
the dynamo and the flow from the battery in amperes 
to the lamps or other accessories (except the starting 
motor) an ammeter is attached to one of the battery 
terminals so that all current passing into or out of the 
battery, except that to the starting motor, is indicated 
by the ammeter at the time of current flow. The amper¬ 
age of the current flowing to the starting motor is so 
great that an ammeter capable of registering it would 
not be suitable for the finer work of charging and lamp 
current measurement. 

If it is also desired to know the voltage of charging, 
a voltmeter is connected to the positive and negative 
sides of the charging wires from the dynamo to the bat¬ 
tery in such a way that the voltage is indicated when¬ 
ever the battery is being charged, but protected by the 
cut-out so that the battery cannot discharge through 
the voltmeter. 

Switches. In order to control the passage of the 
electric current from one part of the system to an¬ 
other so that it may be used when desired, various 
forms of switches are provided that may be operated 
(opened or closed) by the driver. Switches are placed 
in the lines going to the different sets of lamps as head, 


Section 4 

12 ELECTRIC LIGHTING AND STARTING 

side, tail, dash, etc., to the starting motor and to any 
other parts that sometimes require current. 

Wiring. The various parts of the system will be 
connected by wires arranged in such a way that the 
processes of battery charging, lighting and engine 
starting may be accomplished. In some cases these 
wires are provided with fuses at some point in their 
travel so that should too great an amperage pass 
through the wire the fuse will melt and break the cir¬ 
cuit. Too great an amperage might destroy the lamps, 
damage the battery or burn out some of the wires or 
coils on the car. The fuses prevent this, and by burn¬ 
ing out call attention to the trouble that caused the ex¬ 
cessive flow, and are themselves easily replaced. 

When two or more wires are to be joined at some 
point on the car the joint is often protected with a 
small metal box inside of which the joint is made. This 
box has a cover screwed on and protects the joint 
against weather and accidental damage. This type of 
covering is called a junction box. 

Should it be convenient to bring a number of wires 
to a point on the dashboard or some other accessible 
place, the insulating plate to which they all lead is 
called a distribution panel. The switches are often 
mounted on a distribution panel. 

Starting Motor. Attached to the engine by gears 
or chains is an electric motor. When current from 
the battery is sent to this motor through the starting 
switch it causes the gasoline engine to turn rapidly 
enough to start the engine. There are only four parts 
to the starting system: the motor, the starting switch 
and the wires connecting the motor and switch to the 
battery. The gearing through which the motor is con- 


ELECTRIC LIGHTING AND STARTING**"13 

nected to the engine is considered as part of the start¬ 
ing system. 

Systems in Use. It is a peculiar property of electric 
machines that they will act either as a dynamo, turn¬ 
ing power into current, or as a motor, turning electric 
current into power. No change whatever is necessary. 
Whenever the dynamo is caused to turn fast enough 



STARTING MOTOR INSTALLATION. 

Drive to flywheel through gear reduction and overrunning clutch, gears 
being slid into mesh by the same movement that closes the starting switch. 
The starting switch is on top of the gear case. 

so that its voltage is higher than that of the battery it 
will act as a dynamo and charge the battery. When¬ 
ever the current coming from the battery is higher 
than that of the dynamo in voltage the dynamo will act 
as a motor and deliver powerr. This fact is taken ad¬ 
vantage of in some systems which have only one unit, 








Section 4 

14 ELECTRIC LIGHTING AND STARTING 

which acts as a motor to start the engine, then as,a 
dynamo to charge the battery when driven by the en¬ 
gine. This arrangement is called a single unit system 
with a motor-generator. 

A generator may easily be used in place of a mag¬ 
neto by attaching the parts necessary for transforming 
the current to one of high voltage and the parts that 



THREE UNIT OR SEPARATE UNIT SYSTEM (AT LEFT) AND ONE 
UNIT OR COMBINED UNIT SYSTEM (AT RIGHT). 

cause the spark to come at the right time and in the 
right cylinder. When the dynamo and magneto are 
combined in one unit we would have a two-unit system 
with a generator-igniter. 

When dynamo, starting motor and magneto are sep* 
arate from each other the system is called a two or 
three-unit system or a separate unit system. 

In some types the dynamo, starting motor and mag- 













„ „ „ Section 4 

ELECTRIC LIGHTING AND STARTING 15 

neto are all combined in one unit and the system is then 
called a single unit or combined unit system. 

The separate unit system is used in a majority of 



COMBINED DYNAMO AND STARTER WITH SEPARATE MAGNETO 
CAT LEFT) AND COMBINED DYNAMO AND IGNITER WITH 
SEPARATE STARTER (AT RIGHT). 


installations, the combined motor-generator coming 
next in popular favor. 
























THE DYNAMO. 


The dynamo used in automobiles is composed of (a) 
the armature which carries coils of wire in which the 
current is generated, (b) the fields, which are the mag¬ 
nets producing the lines of force that pass through the 
armature coils, (c) the commutator, which changes the 
alternating current produced in the coils to a. direct cur¬ 
rent for charging the battery, (d) the brushes, which 
collect the current from the commutator and the case 



“REX” LIGHTING GENERATOR WITH CUT-OUT AND REGU¬ 
LATOR IN SAME CASE. 

which encloses these parts, also the separate pieces and 
attachments which make up these parts. 

The dynamo generates current by induction, the 
coils on the armature being so arranged or moved that 
the lines of force first increase then decrease in the 
coil and in so doing change their direction of travel 
through the coils. 

Construction and Theory. To understand the action 

16 


ELECTRIC LIGHTING AND STARTIN(f“°17 

of the dynamo in generating current first consider that 
the ends of two magnets are separated by a space of 
three or four inches. If one of these ends is a positive 
pole and the other a negative pole there will be mag¬ 
netic lines of force passing through the air from the 
positive to the negative pole. 

Now imagine that there is a piece of soft iron placed 
between the poles. The lines of force would then travel 
through the iron from one pole to the other. Next 
imagine that this piece of iron between the poles is 
carried on a shaft passing through its center at right 
angles to the lines of force. The iron can then be 
turned on the shaft so that the end that was nearest the 
positive pole will be nearest the negative and the end 
that was nearest the negative will be nearest the posi¬ 
tive. The lines of force would then be passing through 
the iron piece in the opposite direction to what they 
were before the iron was turned end for end. 

When the iron piece is turned only half way so 
that it stands at right angles to the path of the lines 
of force, the lines will not travel through the length of 
the iron but across the piece. When the iron is slowly 
turned from this last crosswise position the ends of the 
iron will gradually come closer to the ends of the mag¬ 
nets until the lines of force will take up their path 
through the length of the iron piece once more. When 
the ends of the iron piece are directly opposite the 
ends of the magnets the lines of force will have the 
easiest path but as the turning of the piece on the shaft 
is continued it will become harder and harder for the 
lines of force to travel through the iron until just before 
the iron is crosswise between the magnets, the lines 
of force stop passing through the length of the piece 


Section 4 

18 ELECTRIC LIGHTING AND STARTING 



PRINCIPLE OF DYNAMO ACTION. 





































































Section 4 

ELECTRIC LIGHTING AND STARTING 19 

of iron. As the iron continues to turn it will come into 
the position where the lines of force will again pass 
through its length. It will be seen that each time the 
piece of iron makes one complete turn the direction of 
the lines of force through the iron changes its direc¬ 
tion twice, the strength of the lines of force through the 
piece of iron decreases and then increases twice. 

Now, if we wind a coil of wire around the piece of 
iron that is carried on the shaft between the magnets, 
the path of the lines of force through the center of the 
coil of wire (which is filled by the piece of iron) will 
be the same as the path of the lines of force through 
the iron alone. That is, the strength of the lines of 
force through the coil will increase and decrease twice 
during each revolution. It will be remembered that 
when the strength of the magnetic field or lines of 
force is increased and then decreased in or around a 
coil of wire a current of electricity is induced or gen¬ 
erated in the coil of wire. This is the principle of the 
electric dynamo. 

Fields. The fields or field magnets of the dynamo 
are the magnets that produce the flow of magnetic lines 
of force in which the coils of the armature are carried. 

In many cases the field magnets are U shaped or 
horseshoe shaped, the armature with its coils being 
carried between the ends or poles of the magnet. Inas¬ 
much as there is a flow of magnetic lines of force be¬ 
tween the poles it is possible to cause them to pass 
through the coils of the armature and generate the 
current as the armature is turned. 

Some dynamos have permanent field magnets, others 
have electro-magnets for the fields, these electro-mag- 


Section 4 

20 ELECTRIC LIGHTING AND STARTING 

nets receiving their current from the current produced 
by the dynamo. 

Inasmuch as the armature is intended to rotate it is 
made round. It is desirable that the air space between 
the iron of the armature and the ends of the magnets 
be as small as possible, just enough so that the arma¬ 
ture iron will not actually touch the ends of the mag¬ 
nets. In order to bring the poles or ends of the 



FIELD MAGNETS, BEFORE AND AFTER APPLYING THE 
WINDINGS. 


magnets very close to the armature these ends are ex¬ 
tended to within one-thirty-second of an inch or less 
of the armature and are made hollow so that the two 
poles or ends form a cylindrical shaped tunnel for the 
armature to turn in. The two poles do not actually 
touch each other but enclose the armature so that the 
poles are only about one-half to one inch apart. These 
extensions of the magnet ends are called the pole 
pieces. They are sometimes in one piece with the mag- 






ELECTRIC LIGHTING AND STARTING^ll 

net, sometimes separate pieces fastened to the ends of 
the magnet. The hole that the armature turns in is 
called the armature tunnel. 

The field magnets are fastened to the case tnat en¬ 
closes the parts of the dynamo, the case often forming 
a part of the body of the magnet. 

Armature. In order that the dynamo may generate 



DYNAMO OR MOTOR FIELD WINDINGS. 


a fairly large quantity of current the armature usually 
carries a number of coils, from eight up to twenty or 
thirty. It will be seen that with a large number of coils 
the flow of magnetic lines of force is always changing 
in one of them so that the current produced by an 
armature of many coils is more steady and continuous 
in its flow than would be the case with only one coil. 
In order to make this flow even more steady and uni- 



























Section 4 

22 ELECTRIC LIGHTING AND STARTING 

form dynamos are built with more than two fields so 
that there are four, six or eight poles sending lines of 
force through the armature coils, half the poles being 
positive and the other half negative. This type of ma¬ 
chine is called a four, six or eight-pole dynamo. 

When the lines of force pass through the armature 
coil in one direction, the induced current in the coil 
flows around the coil in a certain direction. When the 
direction of flow of the lines of force through the coil 


DYNAMO FRAM£ 



DYNAMO PARTS. 


is reversed the flow of .induced current around the 
coil is also reversed. 

If one end of a coil delivers positive current the 
other end will be negative. The terminals of the coil 
will continue this way during half the revolution of the 
armature. During the other half revolution of the 
armature the flow in the coil is reversed so that the 
end that was negative is now positive and the end that 
was positive is now negative. 







Section 4 

ELECTRIC LIGHTING AND STARTING 23 

If we collect the electric current from the armature 
coils just as it is produced, the flow will first be in one 
direction and then in the other, this current being called 
an alternating current. In order to charge a storage 
battery it is necessary that the flow be continuous in 
one direction. This makes it impossible to charge a 
battery with an alternating current. 

The iron of the armature on which the coils are 
wound is called the armature core and the coils are 
called the armature windings. 

Commutator and Brushes. The purpose of the com¬ 
mutator is to give all the positive current flow from the 
armature to one wire of the circuit and to give all the 
negative flow from the armature coils to another wire 
of the circuit so that one wire will always be positive 
and the other one will always be negative. 

On one end of the armature shaft is placed a copper 
cylinder which extends all around the shaft. This cyl¬ 
inder is cut into as many sections (running lengthwise 
of the shaft) as there are ends of the armature coils. 
That is, there will be twice as many pieces in the cop¬ 
per cylinder as there are coils because each coil has 
two ends. For the purposes of explanation we will 
consider a commutator or cylinder divided into only 
two parts, each part extending half way around the 
shaft. This would be suitable for an armature having 
only one coil. 

We will now mount two brushes (pieces of carbon 
or copper) so that one brush touches the cylinder or 
commutator on one side and the other brush touches 
it on the other side directly opposite. These brushes 
will remain stationary while the commutator and ar¬ 
mature turn. 


Section 4 

24 ELECTRIC LIGHTING AND STARTING 

With the armature coil in position so that the mag¬ 
netic lines of force flow straight through its center we 
will place one of the brushes so that it is touching 
one half of the copper cylinder at one end of the half 
so that as the commutator is turned this half will 
pass under this brush during half a turn. 

The other brush, being directly opposite, will be at 



PRINCIPLE OF THE ARMATURE COIL, COMMUTATOR 
AND BRUSHES. 

the end of the other half of the copper cylinder and 
as the cylinder turns this other brush will stay in con¬ 
tact with that half of the commutator for the same half 
turn. 

One end of the coil is attached to one-half the com¬ 
mutator, the other end being attached to the other half. 
It will be remembered that one end of the coil de- 















Section 4 

ELECTRIC LIGHTING AND STARTING 25 

livers positive current during half a revolution while 
the other end of the coil is negative during the same 
half revolution. 

Inasmuch as one end of the coil is attached to one- 
half the commutator and one-half the commutator will 
be in contact with one brush during half a revolution, 
it will be seen that this brush will receive positive cur- 



armature windings attached to commutator bars. 

rent during this half revolution. For the same reasons 
the other brush will be negative at this time. 

When the coil has made a half revolution, the side 
that was going down and delivering positive current 
will start up and will then become negative. The half 
of the commutator attached to this side of the coil 
will pass from under the positive brush and will come 
in contact with the negative brush on the other side at 



Section 4 

26 ELECTRIC LIGHTING AND STARTING 

the same time that the coil stops delivering positive 
current and becomes negative. The other end of the 
coil (with its half of the commutator) will have passed 
under the positive brush just as it starts to deliver a 
positive flow so that one of the brushes is always in 
contact with the part of the commutator that receives 
positive current while the other brush is always in con¬ 
tact with the side or half of the commutator that is 
negative. 

One of the brushes is called the positive brush and 



BRUSH WITH PIGTAILS ATTACHED. 

the other one the negative brush, the brushes being at¬ 
tached to the positive and negative wires. 

The parts of the commutator are called commutator 
segments or commutator bars and they are separated 
and insulated from each other with thin pieces of mica 
or other insulating material. 

The brushes are connected to the wires leading from 
the dynamo by small flexible pieces of wire attached to 
the brush which are called pig tails. 

The brushes are carried in some form of insulation 
and this insulation is held by the brush holder. The 
brush holder is fastened to the frame or case of the 


Section 4 

ELECTRIC LIGHTING AND STARTING 27 

dynamo. In order to keep the brushes in contact with 
the commutator there are small flat or coiled springs 
held by the brush holder which keep the brush up to 
its work. These springs always have some means of 
increasing or decreasing the pressure on the brushes. 

Brushes are made from a very fine, smooth, soft 
grade of carbon or from a mixture of carbon and graph¬ 
ite or from copper or from copper and carbon made to¬ 
gether. 

There are always as many brushes for collection of 
current as there are poles or ends of magnets in the 
fields. There may also be additional brushes that col¬ 
lect current from the commutator or deliver current to 
the commutator for purposes of regulation. 

Dynamo Current Output. The current delivered 
from the dynamo is measured in volts and amperes. 
However, the voltage in all the lines of wire on the car 
is determined by the voltage of the battery, the battery 
holding the voltage practically the same as its own 
pressure under all conditions. The actual voltage de¬ 
livered by the dynamo can therefore be neglected, as 
it has no effect on the system. 

The output of the dynamo in amperes is very im¬ 
portant, both that it be enough to keep the battery 
properly charged at all times under normal or abnormal 
conditions and that it is not too great for the good of 
the battery in charging. 

The output of the average dynamo at ordinary car 
speeds is from ten to twenty amperes. The output re¬ 
quired depends on the amount of current needed by the 
lamps, starter and other devices on the car and also 
on the size or capacity of the battery in ampere hours. 
The size of the battery really depends on the amount of 


Section 4 

28 ELECTRIC LIGHTING AND STARTING 

current required to be held in reserve for the various 
electrical parts, the dynamo size therefore depends on 
the current requirements of the car. 

If all the current-consuming devices be placed in 
operation at one time (all lamps and other devices or¬ 
dinarily used), the ammeter will show the number of 
amperes being drawn from the battery. The lamps, 
etc., may then be turned off so that there is no with¬ 
drawal from the battery and the engine run at a speed 



COMMUTATOR HOUSING WITH BRUSHES AND BRUSH HOLDERS. 

that would correspond to about fifteen miles per hour 
or the car may be run on the road at this speed. 

The amperes delivered by the dynamo at this speed 
with all the current consumers out of use and the cur¬ 
rent in amperes drawn from the battery with the en¬ 
gine idle and all devices turned on should be just about 
equal. That is, the output of the dynamo at fifteen 
miles per hour should be the same as the requirements 
of all the lamps, etc. This will keep the battery prop¬ 
erly charged. 





ELECTRIC LIGHTING AND STARTING*™!? 

The greatest amount of trouble in all systems in gen¬ 
eral is from discharged or partly discharged batteries. 
The importance of proper generator output may be 
realized from this fact. 

The capacity of the storage battery is measured in 
ampere hours. As explained, the ampere hour is the 
amount of current delivered in one hour at a flow of one 
ampere and the ampere hour capacity of the battery 
is the number of amperes the battery would deliver 
for one hour or the number of hours that the battery 
would give a flow of one ampere. Thus a 120-ampere 
hour battery would give a flow of one ampere for 120 
hours or (theoretically) a flow of 120 amperes for one 
hour or any other combination of hours and amperes 
which multiplied together would equal 120. 

The current output of a dynamo in amperes is sup¬ 
posed to be not more than one-eighth of the battery 
capacity in ampere hours under any conditions. 

Ftom the above you will see that the capacity of the 
battery must be enough so that the current consumed 
by all the lamps, etc., in amperes will not be more than 
one-eighth of the battery capacity. This is true for 
the reason that the dynamo output at ordinary speeds 
must equal the current used by all the lamps and other 
devices and this output must not be more than one- 
eighth battery capacity. 


FIELD WINDINGS. 


The field magnets of a dynamo may be permanent 
magnets or they may be electro-magnets. If they are 
permanent magnets there is no coil or winding re¬ 
quired to make them magnetic and the current is taken 
from the brushes to the work of lighting the lamps, 



PERMANENT MAGNET DYNAMO. 

Centrifugal cut-out is located in the cylindrical case at the left hand end. 


etc., without any of the current being used for mag¬ 
netizing the fields. 

Most dynamos in use for lighting and starting sys¬ 
tems have their fields made from electro-magnets hav¬ 
ing coils of wire around the soft iron magnet core, the 

30 






ELECTRIC LIGHTING AND STARTING Ctl °3I 

passage of electric current through these coils making 
the iron into a magnet. The current for these mag¬ 
netizing coils is received from the dynamo itself by tak¬ 
ing a part of the current generated and using it for 
this purpose. 

It might be said that the soft iron of the fields would 
give no flow of magnetic lines of force through the 
armature to begin with if soft iron does not remain a 
magnet. This would prevent the dynamo from start¬ 
ing to generate current and of course there would be 
no current made to use for magnetizing the field coils. 
It should be understood, however, that no piece of 
iron, however soft, ever loses all its magnetism under 
ordinary conditions. There is a very small amount of 
magnetism left in the field cores at all times and this 
magnetism causes enough lines of force to flow through 
the armature coils to start the generation of more cur¬ 
rent, this current then strengthens the field magnets 
and the output of the dynamo rapidly builds up to 
normal. In actual practice this building up only re¬ 
quires a few seconds. 

Series Winding. It will be understood that the coil 
of wire around the iron core of the field magnets has 
two ends. It will also be understood that there must 
be a positive and a negative wire leading from the 
dynamo to the outside battery charging and lighting 
circuits. 

We might run one wire directly from the positive 
brush to the work and another wire directly from the 
negative brush to the work just as is done with perma¬ 
nent magnet machines. This would not leave any way 
of taking care of the field windings. 

In order to magnetize the fields we will run the cur- 


(Section 4 

32 ' ELECTRIC LIGHTING AND STARTING 

rent from the brushes through the field windings. To 
do this we will run the wire from one brush (either 
positive or negative) directly to the work. 

From the other brush, however, we will run the wire 
to one end of the field coil and from the other end of 
the field coil we will run another wire to the work. It 
will thus be seen that all the current coming from this 
last brush must pass around the field-coil winding be¬ 
fore going to the work. After the current goes to the 
work of battery charging or lamp lighting it returns 
directly to- the other brush without passing through 
the field winding, inasmuch as the other brush was con¬ 
nected directly to the work. This method of supplying 
current to pass around the field coils is called series 
winding and the machine is said to be a series-wound 
dynamo or motor. 

Shunt Winding. Consider the dynamo with its field 
coils again, but without any wires from the brushes to 
the field or to the work. 

This time we will run a wire from each brush di¬ 
rectly to the work without having either of them con¬ 
nected to the field coil. 

The field coil in this case will be made from a great 
many turns of very small wire so that its resistance 
will be much higher than the resistance of the outside 
circuits to the work. 

We will then run a wire from one brush to one end 
of this fine field winding and another wire from the 
other brush to the other end of the field coil. 

When the current comes from the armature wind¬ 
ings into the brushes the greater part of it will take 
the path of least resistance, that is, it will go from the 


ELECTRIC LIGHTING AND STARTING^M 



FIELD WINDINGS. 

C, Cut-out; R, Regulator causing action or idleness of bucking coil; S, 
Starting switch. 



































































Section 4 

34 ELECTRIC LIGHTING AND STARTING 

brush into the wire that leads to the work. A small 
part of the current, however, will pass into the wire 
that leads to the field coil and will pass around the field 
coil and will then return to the other brush from the 
other end of the field coil. 

The amount of current passing through the field 
will all depend on how many times greater the resist¬ 
ance of the field coil is than the resistance of the out¬ 
side working circuits. The coil is usually made of 
such size and length that one-twentieth of the total 
current from the brushes goes through the field coil, 
the balance going to the work. This type of winding is 
called shunt and the machine is called a shunt wound 
dynamo or motor. 

Compound Winding. Should we take a shunt 
wound dynamo and place a series winding around the 
field magnets in addition to the shunt winding already 
there it would form a compound winding and the 
machine would be called a compound wound dynamo 
or motor. 

It was explained that when a current passes around 
a magnet in a clockwise direction the end of the mag¬ 
net you are looking at will be negative and the other 
end positive. In a compound wound dynamo both 
series and shunt coils must be wound in such a way 
that both windings make a positive pole at one end 
of the magnet and a negative pole at the other end. 

Differential or Bucking Coil Winding. Should we 
take a shunt wound machine and place a series wind¬ 
ing around the field magnets in such a way that the 
shunt would make one end of the magnet positive 
while the series winding tried to make the same end 
negative we would have a differentially wound ma- 


Section 4 

ELECTRIC LIGHTING AND STARTING 35 

chine and the series winding would be called a buck¬ 
ing coil. 

If the ampere turns of the shunt winding were 
greater than the ampere turns of the series then the 
shunt winding would cause the poles of the magnet 
to become positive and negative according to the di¬ 
rection of flow around the shunt coils. 

The stronger the series coils then became the more 
their effect would tend to overcome the effect of the 
shunt coils and the magnet would become weaker and 
weaker as the force of the bucking coil became strong¬ 
er and stronger. When both coils were of the same 
strength in ampere turns the magnet would be dead 
and would have no power or magnetic field. Should 
the series coil then become stronger than the shunt 
the magnet would again become stronger but the pole 
that was positive would be negative and the one that 
was negative would be positive and the brushes and 
outside wires would also change their polarity. 

Characteristics and Uses of Windings. Each meth¬ 
od of field winding as well as permanent field magnets 
have their peculiar points and are suitable for certain 
work. In some cases permanent field magnets also 
have a field coil wound on them. This arrangement 
and the differential winding are used for purposes of 
regulation. 

In the series winding it will be seen that the less 
current goes to the work the less will pass around 
the field magnets and the weaker they will become. 

It is a law of electricity that the stronger the field 
magnets are in a dynamo the greater the output of 
that dynamo will be in amperes, and the weaker the 


Section 4 

36 ELECTRIC LIGHTING AND STARTING 

field magnets are the less will the amperage of the 
dynamo become. 

It is also a law of electricity that the greater the 
resistance of a circuit or conductor the less current 
will flow through it provided the voltage remains the 
same. 

In a series wound dynamo having more work (more 
battery resistance) in the outside circuit the flow 
through the circuit will be less because more work 
means more resistance and more resistance means less 
flow. 

If there is less flow through the outside lines there 
will be less flow around the field coils because the cur¬ 
rent to the work all passes around the field coils. 

If there is less current flowing around the fields the 
field magnets will be weaker and the output of the 
dynamo will become less just when we need a greater 
output to take care of the extra work. 

This makes series winding unsuitable for use in 
dynamos but the series winding is used for motors, 
producing the best type of motor for starting an engine. 

When a series wound machine is used as a motor 
all the current received from the battery to be turned 
into mechanical power by the motor passes around 
the field winding on its way to one of the brushes. 

The harder the work to be done by the motor the 
greater will be the flow of current required. 

The greater the flow of current to the motor and 
through the fields the stronger the field magnets be¬ 
come and this increases the strength or pull of the 
motor in proportion to the current flowing. 

It will be seen that a series wound motor is strong¬ 
er the harder the work it has to do so that it is very 
well suited to starting the automobile engine. 


ELECTRIC LIGHTING AND STARTINg“°37 

It will be remembered that the battery maintains 
the voltage at a constant point at all times. It was 
also explained that it is the voltage or pressure of a 
current that forces it to flow through conductors. 

The windings of a shunt wound dynamo are so 
high in resistance that they take but a very little of 
the current generated, but, just as long as the voltage 
remains the same (as it always does) this small amount 
of current ’ will pass through the shunt winding. 
Whenever a generator runs at all it makes at least one- 
twentieth of its normal output and this is enough for 
the shunt windings. Therefore, the flow of current 
around a shunt field will remain practically the same 
no matter what the outside conditions. 

As long as the flow remains the same the strength 
of the field magnets will remain the same and this 
steady field strength will cause the dynamo to give a 
fairly steady output regardless of the conditions under 
which it may be working. This makes the shunt 
winding very suitable for dynamos. 

A shunt winding is not well suited for motors be¬ 
cause the resistance of the shunt field is so high that 
it cannot increase its strength to take care of extra 
work as the series wound motor can. 

Combining the two windings in a compound wound 
machine makes it well suited for work either as a 
dynamo or motor. The shunt winding prevents the 
output from dropping when there is extra work for 
the dynamo and the additional flow through the series 
winding required by the extra work strengthens the 
field and the output to a certain extent. 

When a compound wound machine is used for a 
combined dynamo and starting motor, arrangements 


Section 4 

38 ELECTRIC LIGHTING AND STARTING 

are sometimes made so that only the series winding 
is used while the machine acts as a motor by having two 
separate commutators, one for each field winding. 
Special means are provided so that the balance of 



COMPOUND WOUND DYNAMO AND MOTOR. 

D, Dynamo commutator with shunt field winding attached to brushes i 
and 2 , giving ordinary shunt wound dynamo action in generating; M, Start¬ 
ing motor commutator, current passing through starting switch (S) to 
brushes 3 and 4, exciting series field windings only. 


power between the shunt and the bucking coil in a 
differential machine may be changed in such a way 
that the output of the dynamo is kept at the rate de¬ 
sired. 
























ADJUSTMENT, OPERATION, CARE AND RE¬ 
PAIR OF THE PARTS OF DYNAMOS 
AND MOTORS. 


Mounting. Dynamos and motors are usually 
mounted rigidly on the engine crank case or on the 
frame that carries the engine. If on the transmission 
case or frame of the car special care must be used that 
the mounting is strong enough so that the shaft is held 
in line with the gears or sprockets while under the 
strain of generating current or starting the engine. 

Some types of dynamos may safely be mounted on 
iron bases without having the lines of force pass 
through the iron base. If an electric machine is en¬ 
cased with iron it will of course be safe to carry it 
on an iron base. If the magnets are apparently of 
the horseshoe, circular or U shape it will not be best 
to mount them in such a way that the ends of the 
magnets come close to a piece of iron that extends 
from pole to pole. While mounting this type of 
machine on an iron base may not affect the efficiency 
it can do no good and may do harm. In any case a 
base mounting of brass, aluminum or some other 
metal than iron or steel will be most satisfactory. 

Dirt and Moisture. While modern dynamos and 
motors are made practically dirt and waterproof it 
is best to give them ordinary care to prevent either 
moisture or dust collecting on or near the case. 

Moisture in a thin film will form a fairly good elec¬ 
trical conductor and might easily provide a path for 
the leakage of current under some conditions. 

39 


Section 4 

40 ELECTRIC LIGHTING AND STARTING 

Dust or dirt of any kind may be a conductor itself 
and even if not a conductor, collects water and oil 
which are sufficient to make a leakage of current. 

Fine dust from the brushes and commutator will 
collect inside the case and may easily form a con¬ 
ducting path if' deposited on the brush holders, the 
insulation or other exposed parts carrying current. 
In addition to this trouble, dust will work into the 
bearings in time and cause a more rapid wear than 
normal. 

The dynamo or motor should be opened and thor¬ 
oughly wiped out with a clean cloth once every six 
months or even oftener in the case of the dynamo. 

Assembling and Disassembling. In taking a motor 
or dynamo apart great care must be used that all out¬ 
side wires and connections are first removed before 
the machine is loosened from its base and driving 
parts. 

When opening the case or removing any of the cov¬ 
ering plates they must be drawn away from the ma¬ 
chine carefully and in a line straight out from the case 
because these covers often carry delicate electrical 
contacts, springs, brushes and other parts which are 
liable to damage. 

Before attempting to remove the brushes the pig 
tails must be loosened from their terminals and the 
brush springs must be carefully removed or set to one 
side of the brush so that the spring will not be bent 
or broken in removing. If the spring adjustment is 
loosened when removing the brushes this adjustment 
must be made right again as directed below. When 
the brushes are withdrawn from the holders or when 
the holders and brushes are taken off together care 


_ Section 4 

ELECTRIC LIGHTING AND STARTING 41 

must be used that they are marked in such a way 
that the same brush will be replaced in the same place 
and that the same side of the brush will be toward the 
front of the armature as was the case before remov¬ 
ing. Brushes wear to a good fit in the position in 
which they are originally mounted and they will not 
fit if replaced in any other position. 

After the brushes and brush holders are removed 
‘the armature may be taken out of the armature tun¬ 
nel by taking off one or both of the end bearings of 
the armature shaft. These are usually annular ball 
bearings held in housings or cases fastened to the out¬ 
side of the dynamo or motor case with small screws 
or bolts. 

The fields and field windings should usually be left 
in the case except in case of severe damage or break¬ 
age. The ends of the field windings must be carefully 
loosened from everything and withdrawn from any 
holes through which they pass so that the loose ends 
can be traced right up to the point at which they enter 
the field coil. The coil itself will remain on the core 
of the field magnet. These cores are screwed or 
bolted into the case and they must positively be re¬ 
placed so that they occupy exactly the same position 
and stand the same way in the case when they are 
replaced. 

Needless to say, the connections and terminals must 
all be marked so that they may be connected in the 
same way as originally found. 

Terminal and Joint Care. The ends of all wires in 
the dynamo or motor as well as at all other points in 
the system should have copper or brass terminals at¬ 
tached and soldered to them so that the hole in the 
'22 


Section 4 

42 ELECTRIC LIGHTING AND STARTING 

terminal and not the wire itself may be placed over 
the binding screw. 

When the terminals of wires are fastened to the 
binding screws the nuts or screws must be screwed 
down tight and fastened in place whenever possible. 
Before fastening terminals see that all surfaces in 
contact are bright and clean and free from all dirt 
and oil. 

Simply twisting the ends of two wires together does 
not make an electrical joint of low enough resistance 
to be allowed in electric lighting and starting work. 
The wires must be thoroughly scraped and cleaned, 
twisted together tightly and soldered. The joint 
must then be covered with a winding of rubber tape 
and this covered with a winding of several layers of 
ordinary friction tape. 

Armature Windings. The winding of coils on 
armatures and fields is a trade in itself and should 
never be attempted in the ordinary shop, for failure 
is almost sure to be the result. 

Should a test at the dynamo terminals while the 
dynamo is running show that no current is being gen¬ 
erated it may be possible that the windings of the 
armature are broken or burned or that they have be¬ 
come short circuited or grounded. The facts may be 
found by testing for broken circuits, shorts and 
grounds as directed under Lamps and Wiring. When 
one end of a test wire is held in contact with any com¬ 
mutator segment the test lamp or voltmeter should 
show a passage of current if the other test wire is held 
against any other commutator segment. If one seg¬ 
ment is found which does not allow the flow of cur¬ 
rent the wire from this segment to its coil is broken 


Section 4 

ELECTRIC LIGHTING AND STARTING 43 

or burned off, the wire in the coil is broken or burned 
at some point or the wire of the coil or to the segment 
is short circuited or grounded to some other wire or 
coil or to the core or shaft. This will be true provid¬ 
ing the trouble is not in the commutator or other parts 
outside of the armature windings. 

If the broken wire is in plain sight it may be soldered 
as directed in this section, otherwise the armature 
must be removed and sent to the maker or to some 
electrical repair company having facilities for this 
class of work. 

It may also be possible that the insulation may be 
worn or scraped from some part of the wire or wind¬ 
ing in which case it may be replaced with friction 
tape. 

Armature Core, Shaft and Bearings. Nothing will 
happen to the armature core except through an acci¬ 
dent that makes the entire machine worthless. 

The armature shaft might become bent, allowing 
the core to touch the pole pieces. It should be re¬ 
moved from the machine and straightened cold if only 
slightly bent near the end, but otherwise the armature 
must be sent to the maker for a new shaft. 

The bearings require the care and adjustment that 
any other bearings of the same type require, all of 
which is given in the section on Car Parts. 

Commutator. Should the commutator not receive 
proper care its surface will become rough, pitted and 
scratched. In this condition it causes rapid wear of 
the brushes, excessive sparking at the brush contacts 
and an irregular output and loss of current produced. 

The surface of a commutator should be a dark brown 
or dark copper color and should be covered with a high 


Section 4 „ 

44 ELECTRIC LIGHTING AND STARTING 

polish and glazed look. This would be the best pos¬ 
sible condition. If the surface shows a bright fresh 
copper color the brushes are cutting and they should 
be examined for hard or sharp spots or possibly the 
brushes were not secured from the maker and are not 
suited to the machine. 

To place a damaged commutator in good condition 
first examine it carefully to make sure that the surface 
is perfectly round. See that there are neither high nor 
low segments or places on the segments, also see that 
the insulation is good between the segments and that 
the insulation does not stick up above the surface 
at any point. Then look to see that there are no par¬ 
ticles of copper on the insulation so that they extend 
from one segment to the next. If there are particles 
of this kind remove them with a pocket knife blade. 
This precaution should be taken both before and after 
caring for the commutator. 

Should there be noticeable high or low spots or 
should insulation project above the surface remove 
the armature and commutator and place in the lathe 
and take a very fine cut across the face of the com¬ 
mutator to make it perfectly round. 

If the surface is scratched or pitted or rough, but 
still round, remove the brushes from contact with the 
commutator (if in the dynamo) or (if in the motor) 
remove the armature and commutator and place in the 
lathe. The dynamo may be rotated by starting the 
engine. 

Now take a strip of number 00 sandpaper (not emery 
cloth or anything else) almost as wide as the com¬ 
mutator and wrap it over the end of a piece of wood 
so that it may be held against the surface of the com- 


Section 4 

ELECTRIC LIGHTING AND STARTING 45 

mutator. With the commutator rotating hold the 
sandpaper against the surface with slight pressure, 
moving the sandpaper so that it cleans and dresses all 
parts of the width of the commutator. Continue this 
operation until all marks are removed and the com¬ 
mutator is left clean and bright. 

Next wipe the surface of the commutator with a 
clean cloth and then hold a piece of soft pine against 
the rotating surface until the commutator is polished 
and slightly darker in color. 

After finishing the above blow or wipe all the dust 
from the case and parts where it has settled. Use a 
short length of copper tubing to blow through and 
after all the parts are clean the brushes may be re¬ 
placed provided they are in proper condition for use. 

Brushes. The material, pressure, position, shape 
and size of the brushes must all be suited one to the 
other. Except in case of absolute necessity no brushes 
should be placed in any dynamo or motor that are not 
furnished or recommended by the maker of the ma¬ 
chine. The wrong brush will cause excessive spark¬ 
ing, heating, lowering of the output and a discharged 
battery and will wear rapidly and in doing so will 
damage the commutator. 

The contact surfaces of copper brushes should be 
clean and smooth and bright, the contact surfaces of 
carbon brushes should be clean and smooth and slight¬ 
ly polished and should be a dark gray color. 

The contact surfaces of any brush should fit the 
curve of the commutator at all points. 

If the brush surface is rough or pitted or burned it 
may be restored to condition as follows: Take a piece 
of 00 sandpaper of a width slightly greater than the 


Section 4 

46 ELECTRIC LIGHTING AND STARTING 

width of the brush. Pass this strip of sandpaper down 
between the brush and the commutator so that the 
sand side touches the contact surface of the brush. 
Draw the strip back and forth, holding it so that it fol¬ 
lows around the curve of the commutator. This will 
dress the brush surface so that it just fits the curve 
of the commutator. 

After finishing all dust must be wiped or blown 
away from the parts. 

Brush Holders and Insulation. The brush holder 
is usually made of metal and the brush itself is ar¬ 
ranged in an insulating cover of mica, stone or fibre 
which is carried by the brush holder. The brush may 
become grounded to the holder through a cracked or 
broken insulation or from deposits of dust and dirt. 
In some machines the brush slides through the in¬ 
sulation while the holder remains stationary. In other 
machines the holder is carried on a pivot or hinge so 
that the holder and brush swing toward or away from 
the commutator. A possible source of trouble will be 
that the brush becomes stuck or wedged, or the holder 
may-not swing easily on its pivot. In either case the 
brush cannot make proper contact with the commu¬ 
tator, lowering the output and causing sparking at 
the contacts. 

Brush Springs. The strength of each brush spring 
must be the same as each of the other springs in the 
same machine. This pressure on the brush should be 
only enough in any case to prevent sparking and to 
cause the dynamo to give its normal output. Too 
much brush pressure causes rapid wear of both brush 
and commutator. 

The tension of the springs may be tested by taking 


Section 4 

ELECTRIC LIGHTING AND STARTING 47 

a light spring balance or scale and attaching its hook 
to the brush spring or to the brush or the brush hold¬ 
er. Now pull on the balance until the brush just leaves 
contact with the commutator. The pull shown on the 
scale should be the same for all the brushes and if 
not the same, the springs must be adjusted. 

Brush springs must hold the brushes in steady con¬ 
tact with the commutator and to do this they must 
not be bent or broken or sticking. 

Field Windings and Cores. The same things apply 
to the field windings that were mentioned in connec¬ 
tion with the armature windings. In the case of the 
field windings the tests must be continued from the 
point at which the wire enters the field coil to the 
point at which it attaches to the brush or leaves the 
case. 

Providing the field cores are securely attached to 
the case and are in the right position they can give no 
trouble. 

Drive. The drive from the engine to the dynamo 
or from the motor to the engine may be through gears 
or chains. Some of the old dynamos were driven by 
belts or by friction wheels running on the flywheel. 

Should the armature shaft of the dynamo fail to 
turn with the engine running, the trouble will be in 
the driving parts. It takes the form of keys broken or 
sheared off; of broken shafts; loose or broken gears, 
gear teeth or sprockets, or broken chains. 

The gears and chains are repaired and should have 
the care outlined for the various types under the head¬ 
ings in the section on Car Parts. 

With belt or friction drive it is only necessary that 


^‘““electric lighting A nd starting 

the parts be kept clean and dry and tight enough to 
do the driving. 

Overrunning Clutches. In order that the rather 
small starting motor may have power enough to start 
the engine it is necessary to increase its leverage by 
some system of reduction gearing so that the starting 
motor may run at a greater speed than the crank 
shaft turns in starting. This reduction usually causes 
the starting motor to run at a speed of five to fifty times 



OVER-RUNNING CLUTCH. 


that of the crank shaft. There are some systems how¬ 
ever that use a starting motor so large that it takes 
the place of the flywheel and of course turns at the 
same speed as the crank shaft. 

In case the reduction is fifty to one it will be neces¬ 
sary that the starting motor armature turn fifty times 
as fast as the engine crank shaft. Inasmuch as the 
engine will start easily when turned at 100 revolu¬ 
tions a minute this only requires a speed of 5,000 turns 
a minute of the starting motor which is not excessive. 





Section 4 

ELECTRIC LIGHTING AND STARTING 49 

As soon as the gasoline engine begins to operate its 
speed may go up to 1,000 revolutions per minute, 
which would cause the starting motor to turn at the 
rate of 50,000 turns a minute. An armature could not 
be built to stand this speed, therefore it is necessary 
that the starting motor be quickly and automatically 
disconnected from the engine or the gear reduction 
would cause it to run at excessive speed. 

In order to do this a device called an overrunning 
clutch is used which is exactly similar in construc¬ 
tion and operation to the coaster brake on a bicycle. 



OVERRUNNING CLUTCH, ROLLER TYPE. 

The part attached to the engine corresponds to the 
part attached to the road wheel of the bicycle and the 
part attached to the starting motor corresponds to 
the part that is attached to the driving sprocket of the 
bicycle. 

Everyone knows that the rider can pedal a bicycle 
and apply power to the road wheel just as long as 
his feet will stay on the pedals, but should the bicycle 
go faster than he can pedal the road wheel can still 
increase its speed while the rider stops pedaling if 
he desires to. 


Section 4 

50 ELECTRIC LIGHTING AND STARTING 

The overrunning clutch drives the engine from the 
starting motor until the engine speed becomes more 
than the starting motor will turn. At this time the 
clutch releases and the engine can speed up while the 
starting motor can stop. 

Overrunning clutches are made from two circular 
parts, one fitting inside the other. The one part at¬ 
taches to the starting motor and the other part to the 
engine. Holes or slots are cut in the inner part that 
carry balls or rollers. When either part is caused to 
whirl by the starting motor, the balls or rollers fly 
out and wedge between the two parts, driving them 
both as one piece. Should one part now go faster 
than the other, the balls or rollers are forced back into 
the holes or slots because these holes are cut at an 
angle into the inner part. 

The parts of the clutch are enclosed in a case and 
this case should be kept filled with vaseline or light 
transmission grease. Aside from wear in long service 
or breakage nothing will happen to prevent the clutch 
operating properly. 

Small springs are placed back of the balls or rollers 
and should these springs break or should the balls or 
rollers stick the clutch will not take hold. Unless 
from long running without oiling the clutch will rarely 
refuse to release because the power to run the start¬ 
ing motor at such a speed would be so great that the 
parts would surely be separated under all ordinary 
conditions. 

Should the starting motor turn without moving the 
engine trouble may be looked for in this clutch, usually 
through wrong assembling of the clutch parts. 


ELECTRIC LIGHTING AND WIRING. 


Circuits. When current leaves one of the terminals 
of a dynamo or battery it must be able to travel over 
the lines of the working circuit and return to the 
other terminal of the dynamo or battery. Unless the 
current can return in this way there will be no flow in 
any part of the circuit or wires. 

After this current returns to the dynamo it passes 
into the brushes, through the armature windings to 
the other brush and to the other terminal where it 
again leaves the dynamo. The dynamo simply acts 
as a pump, sending the current round and round the 
circuit just as long as the wires have a complete con¬ 
nection from the positive terminal back to the nega¬ 
tive terminal. 

When the current returns to the battery it enters 
and passes from one of the plates to the other and 
then out of the other terminal and circulates the same 
as the dynamo current. 

One of the very first things to look for in case of 
trouble would be loose or broken wires or connec¬ 
tions because these stop the flow in the entire circuit. 
Unless the current can get back to the negative side of 
the source it will never leave the positive, so it makes 
no difference where the broken wire or connection 
may be, it stops the action in all other parts, either 
side of the break. 

More electrical trouble in both lighting and ignition 
is caused by incomplete circuits than by any other 

51 


52 C “° n 4 ELECTRIG LIGHTING AND STARTING 



WIRING DIAGRAM OF COMPLETE STARTING AND LIGHTING 
OUTFIT. (Autolite.) 



























































Section 4 

ELECTRIC LIGHTING AND STARTING 53 

one thing. The user persists in running a wire cor¬ 
rectly to one or more points and then leaving it with¬ 
out giving a return to the place from where it started. 
Unless you are able to trace a complete circuit from 
the dynamo or battery through the work and back 
to the dynamo or battery you are wasting time trying 
to make the parts operate. 

Lamps. The lamp bulbs used in car lighting are 
classified according to their candlepower, the size of 



A BROKEN LAMP CONNECTION MAY AFFECT ONLY ONE 
LAMP IN MULTIPLE WIRING. 


the glass bulb, the material of the filament inside the 
bulb and the type or method of fastening into the 
socket. 

Bulbs may be bought having any candlepower from 
1 to 30. In ordinary use 2 to 20 candlepower is about 
all that is required. As a general rule, head light 
bulbs have a candlepower of 15 to 24. Side lamps 
have 2 to 8 candlepower, tail and rear lamps use 2 to 
4 and dome, dash, speedometer, trouble and similar 
small lamps require about 2 or 3 candlepower. 



















^ELECTRIC LIGHTING AND STARTING 

Lamp bulbs are usually marked with the candle- 
power they are designed to give, this marking being 
either on the glass of the bulb or on the metal that 
holds the glass. In addition to the candlepower mark¬ 
ing the number of volts that the bulb should operate 
on is also marked at the same place. A marking of 
“6v-10cp” would indicate that the lamp would give 
10 candlepower when operated on a 6 volt circuit. 
“4cp-8v” would indicate that the lamp would give 4 
candlepower when operated on an eight volt circuit. 



ELECTRIC SIDE LAMP. 


Bulbs of higher candlepower should not be used to 
replace those burned out or broken. The system 
was designed to carry the load of the lamps furnished 
and placing higher candlepower bulbs in the circuits 
places a greater load on the parts than they were made 
to carry. An increase of two or three candlepower 
at one place on the car may be allowable but a general 
increase above this amount should not be attempted. 

Bulbs for car lighting are made in a great many 
sizes. There are four standard sizes measured by the 





ELECTRIC LIGHTING AND STARTING****55 

distance through the bulb from side to side, or the 
diameter, in inches. The largest size bulb measures 
2 l/16th inches diameter, the next smaller 1 y 2 inches, 
next to the smallest 1 inch and the smallest size % inch 
in cross diameter. 

The size of the bulb has nothing whatever to do 
with the candlepower of the bulbs. Neither has it 
anything to do with the voltage. 

For instance, a 1 inch bulb may be secured in any 



SMALL ELECTRIC LAMP USING DRY CELLS AS SOURCE 
OF CURRENT. 

standard candlepower and voltage. A % inch bulb 
may have a greater candlepower than a 1% inch bulb. 
The size of the bulb is decided according to the focus¬ 
ing of the lamp in its reflector and if the bulb size was 
2 l/16th no other size will do the work. In every case 
you must make the new lamp of the same size as the 
one broken or removed. 

Inside of the glass bulb is placed a small wire 
through which the current passes, making it white hot 



Section 4 

56 ELECTRIC LIGHTING AND STARTING 

and producing the light. This wire or filament may 
be made of either one of three things. Some bulbs 
are made with the ordinary carbon filament such as is 
found in the older type of small house lighting lamps. 
These bulbs were first used altogether but later were 
partly replaced by bulbs having a tantalum filament. 
The tantalum was almost as strong as the carbon, 
gave a whiter light and produced nearly twice as much 
light with the same amount of current. 


In modern practice the carbon and tantalunf bulbs 



COMPARATIVE SIZES OF LAMP BULBS. 
(One-half actual diameter.) 


have been almost entirely replaced by tungsten fila¬ 
ment bulbs, the tungsten filament being shorter and 
giving nearly three times the light of the carbon and 
not quite double the light of the tantalum bulb on the 
same amount of current. 

Lamp Efficiency, Life and Voltage. The efficiency 
of a lamp is measured in the amount of power it con¬ 
sumes to make one candlepower of light. Electrical 
power is measured by watts, so the efficiency of a lamp 
is measured by the number of watts it takes to make 
one candlepower. 




Section 4 

ELECTRIC LIGHTING AND STARTING 57 

This depends to a certain extent on the age of the 
lamp and on its quality, but the greatest factor is the 
material of which the filament is made. 

A carbon bulb requires from 2 % to 3 watts per 
candlepower. 

Tantalum requires from iy 2 to 2 watts per candle- 
power. 

Tungsten bulbs of less than 10 candlepower usually 
take about 1% to l 1 /^ watts per candlepower. 

Tungsten bulbs of 10 candlepower or more take 
about 1 to 1% watts for each candlepower. 

It will thus be seen that the more expensive tungsten 
lamp is much cheaper to use for the light wanted. 

Knowing the efficiency of a bulb we can easily find 
how many amperes of current it should take when 
operated at its correct voltage. 

Supposing we want to find the amperes consumed 
by a 6 volt, 10 candlepower tungsten lamp. 

Ten candlepower requires 1% watts per candlepower, 
making ll 1 ^ watts for the 10 candlepower lamp. 

•We know that the watts equal the volts times the 
amperes so we know that ll 1 /^ must equal 6 (volts) 
times the amperes used by the lamp. 

Dividing 1D/4 by 6 gives us 1%> which would be 
the amperage required by one 10 c. p., 6 volt tungsten 
lamp. 

If this lamp had been a carbon bulb we would multi¬ 
ply the candlepower (10) by the watts required per 
candlepower (3) giving us the watts required by the 
lamp (30). We then divide the watts by the volts (6), 
which gives the amperes used by the lamp, 5. 

This method of finding the amperes may be applied 


23 


Section 4 

58 ELECTRIC LIGHTING AND STARTING 

to any size or type of lamp or to any number of lamps 
on a car. 

At present there are more 6 volt lamps in use than 
any other one voltage. There are also lamps that 
require 2, 3, 3 y 2 , 4, 8, 10, 12, 16, 18, 20, 24 and 30 volts, 
all being in fairly common use. Lamps of 6^ and 7 
volts are used on six volt circuits for the reason that 
decreasing the voltage to a lamp increases its life. A 
six volt lamp on a six volt circuit will usually burn 
with its full candlepower from 100 to 300 hours. If 
the voltage is reduced to 5 or 5% the life of the lamp 
will be almost doubled although its candlepower will 
be greatly reduced. 

The voltage of the current cannot be very easily 
reduced without changing the battery size but the 
lamps may be changed for ones that are supposed to 
take a higher voltage than the battery gives, thus 
securing the same effect of a lower voltage than the 
lamp was built for. 

The higher the voltage of a lamp the easier it will 
be to break the filament, the filament in a high voltage 
being smaller to give the extra resistance required to 
act against the higher voltage. 

The glass of the bulb is fastened into a metal base, 
this base being designed to fasten or screw into the 
socket in the lamp. There are three types of bases 
and sockets in use, the commonest one being the 
Ediswan or bayonet base. The metal carrying the 
bulb has two small pins sticking out about l/16th inch 
on opposite sides of the base. 

This base fits into a tubular socket, slots being cut 
down the sides of the socket for the small projecting 
pins to slide into. These slots are shaped like the cap- 


Section 4 

ELECTRIC LIGHTING AND STARTING 59 

ital letter J, the lower end of the slot being turned up. 
There are spring plungers inside the tubular socket 
against which the bottom of the bulb base presses. 
When the bulb is pressed into the socket and turned 
so that the pins catch in the turned part of the slot 
these plungers hold the bulb tightly in place and at 
the same time provide the electrical contacts for the 
bulb from the lighting lines. This type of base is used 



EDISWAN LAMP BASE. 

almost altogether for car lighting. It is not suited for 
carrying more than five amperes because the connec¬ 
tions heat. 

The small bulbs having a screw base that threads 
into a screw socket are called candelabra bulbs. They 
are very little used on account of their liability to work 
loose. A still smaller size of screw base is called the 
miniature. This is used mostly for temporary deco¬ 
rative lights. 





Section 4 

60 ELECTRIC LIGHTING AND STARTING 

Lamp Connections. Lamps may be connected in 
multiple or parallel with the battery, this being the 
commonest type of connection. This means that a wire 
runs from the battery, carrying the positive current, 
and another wire runs close to the first one and carries 
the negative current. Lamps may be placed at any 
point along the length of these two wires, being fas¬ 
tened between the positive and negative sides. No mat- 



TROUBLE-FINDING LAMP. 

For temporary attachment to special terminals. 


ter how many lamps are connected in multiple each 
one receives the full voltage of the battery. 

For special purposes lamps are connected in series 
with the battery and with each other. The lamps in a 
series line divide the battery voltage equally between 
them. Thus, two lamps in series with a six-volt bat¬ 
tery would each receive three volts; three lamps in se¬ 
ries with a six-volt battery would each receive two 
volts; six lamps in series with a six-volt battery would 
each receive one volt, and so on. 



__ _ Section 4 

ELECTRIC LIGHTING AND STARTING 61 

Inasmuch as all the current passing through one 
part of a series circuit passes through all the other 
parts, the breaking of one lamp, or the removal or turn¬ 
ing off of one lamp in a series circuit, puts out all the 
other lamps in that circuit. 

This fact is made use of in car lighting by having the 
tail lamp and dash or speedometer lamp connected in 
series so that if the tail lamp goes out the dash lamp 
will also go out and warn the driver. These two lamps 
would be of half the battery voltage each but might 
be of different candlepower. 

Any combination of multiple and series connections 
may be used to suit the work to be done. A series set 
of lamps may be connected between the positive and 
negative lines of a multiple circuit or several lamps 
may be inserted in a series line, these lamps being in 
multiple with each other. 

Wiring Systems. Three systems of wiring are in 
use called the two-wire, single-wire and three-wire sys¬ 
tems. The two-wire system is in common use and the 
single-wire system is also very popular. In a two- 
wire system a positive wire is run from the battery to 
any point on the car where current is to be used and 
a negative wire is also run from the battery to each of 
these points. This gives a complete wire circuit both 
from and to the battery and parts of the system. 

The single-wire system has the positive wire lead¬ 
ing from the battery to each of the parts to receive or 
use current. The other side or terminal of each part or 
lamp is connected by a short wire to the metal frame 
of the car. The negative side of the battery is also 
connected to the metal frame of the car so that the cur¬ 
rent returns from the parts or lamps to the negative side 


Section 4 

62 ELECTRIC LIGHTING AND STARTING 

of the battery through the metal frame of the car in 
place of through a wire. The single-wire system is 
provided with fuses in the wires from the battery 
to the parts and lamps. Should the wire become 
grounded the current will flow so fast that this fuse 
will burn out, preventing further loss of current and 
warning the driver or repairman of the trouble. The 
single-wire system saves about one-third the wire and 
allows better insulation of the wire that is used, because 
only one copper conductor is run inside the insulating 
cover in place of the positive and negative wires both 
being in the same cover, or near each other. There 
is thus less chance of leakage from positive to nega¬ 
tive or short circuiting. 

The side, dome and dash lamps of a car require dou¬ 
ble wiring anyway, being so far removed from the 
frame of the car. The double wire furnishes a connec¬ 
tion without the necessity of making ground connec¬ 
tions between the copper wire and steel frame, this 
connection being difficult to make so that it will not 
form high resistance with age and moisture. A two- 
wire system is not usually provided with fuses al¬ 
though this may be done. It should be remembered 
that several standard makes of magnetos will not al¬ 
low the battery current to be grounded so that a sep¬ 
arate battery would have to be used with a single-wire 
system on a car. 

A three-wire system allows of burning lamps of two 
or more different voltages from the same battery while 
the lamps are connected in multiple with each other 
and the battery. 

The commonest three-wire system makes use of a 
nine-cell, eighteen-volt storage battery divided into two 


Section 4 

ELECTRIC LIGHTING AND STARTING 63 



i, Two wire system; 2 , Single wire, grounded return system; 3 , Three 
wire, six and twelve volt system. 
















































































Section 4 

64 ELECTRIC LIGHTING AND STARTING 

sections, one of six cells and twelve volts, the other 
of tfyree cells and six volts. The negative terminals of 
the two sections are joined together and a wire leads 
from this negative to the lamps taking either six or 
twelve volts. 

Should it be desired to furnish twelve volts to any 
lamp it is only necessary to attach one side of the lamp 
to the negative wire, which is called the neutral or com¬ 
mon wire, and the other side of the lamp to the positive 
terminal of the twelve-volt section of the battery. If 
another lamp is to receive six volts, one side may be 
connected to the negative wire and the other side to 
the positive terminal of the six-volt section of the 
battery. 

Any size battery may be taken for a three-wire sys¬ 
tem and this battery may be divided into any size parts. 
The negative terminals of the sections are fastened to¬ 
gether so that the neutral wire can be fastened to the 
joined terminals. 

A battery used for a three-wire system is charged 
as one battery, no attention being paid to the sections. 

The neutral wire of a three-wire battery may be 
grounded to the frame and two wires, each carrying 
different voltage, may be run to various parts of the car. 

Fuses. Fuses are furnished in two forms for auto¬ 
mobile use, one being in the form of wire, a piece of 
which is cut off and placed between two terminals at 
some point in the line. The other form is called a 
cartridge fuse and is made from wire placed in a small 
fibre tube having a copper cap on each end. This 
cartridge is about an inch long and five-sixteenths of 
an inch in diameter. The cartridge is fastened by be¬ 
ing pushed into small spring clips that hold the copper 


Section 4 

ELECTRIC LIGHTING AND STARTING 65 

capped ends. When this style of fuse burns out it 
makes a small black spot on the fibre case near the 
center. 

All fuses are rated according to the amperage they 
are intended to carry. Fuses should be able to carry 
about one-fifth more amperage than the normal re¬ 
quirements of the line in which they are placed. The 
fuse for the headlight lines should be about one-fifth 
more amperage capacity than the number of amperes 
the two headlights will draw as figured by their effi¬ 
ciency and watts or as measured by the ammeter. 
Should one of the wires become short circuited or 
grounded so that a greater flow of current passes 



DISTRIBUTION PANEL AND SWITCH HOUSING. 

through, the fuse will blow out or ourn, preventing 
battery discharge. 

The fuse between the battery and dynamo should 
be large enough to carry one-sixth of the battery ca¬ 
pacity in ampere hours with lead batteries, or one- 
fourth with Edison batteries. There will seldom be a 
fuse in the starting system because the amperage is too 
high. 

Fuses are usually found grouped together in a box 
having a screw cover, this box being near, or a part of, 
the lighting switch box, the distribution panel, or with 
the cut-out or regulator. 


Section 4 A _ _ _ _ 

66 ELECTRIC LIGHTING AND STARTING 

Never replace a fuse with a nail or wire. The result 
might be a discharged battery in time. 

Wires and Protection. The wires for lighting are 
made from stranded flexible cable, or braided wire as it 
is often called. This copper is carried inside of insula¬ 
tion made of rubber, cotton and silk, and the whole is 
often enclosed in a braided or flexible metal covering for 
protection against chafing and breakage. 

The ends of all wires are fitted with copper or brass 
terminals soldered, bolted or screwed to the end of the 
wire and having holes for screws or bolts so that they 
may be tightly fastened to the other parts, making a. 
good contact. 

Wires that are grounded or fastened to the frame 
must have the joint covered with solder so that the 
air cannot reach the joint between the steel and copper. 

Switches. Switches are used for sending the battery 
current to the starting motor and to the lighting lines 
and lamps. 

Starting switches are operated by a lever or pedal or 
button from the driver’s hand or foot. They are built 
with very heavy contacts having a large amount of 
copper because they must carry an electric current of 
more than one horsepower in some cases. Starting 
switches often have two or more contacts, one being 
made after another by the further movement of the 
lever or button. In this case the first contact sends the 
current to the starting motor through a resistance wire 
so that only a small part of the full amount can pass to 
the motor. This causes the motor to start whirling 
with but little force while the gears are placed in mesh 
ready to start the engine. Further movement of the 
starting switch makes the full connection through an- 


Section 4 

ELECTRIC LIGHTING AND STARTING 67 

other contact, giving the starting motor the full power 
of the battery. 

Lighting switches are of four common types: push 
button, rotary, snap and knife. 

Push-button switches are made with two small but¬ 
tons in reach of the driver. When one of these buttons 
is pushed in, contacts are closed in the switch, sending 
the current through to the lamps. When one button is 



TYPICAL STARTING SWITCH. 


pushed in the other one comes out and when the second 
button is pushed in the first one comes out and the con¬ 
tact is broken, cutting off the current. Another type 
having only one button is made, this button being 
pushed in or out to break or make contact. There 
must be one push-button switch for each lamp circuit 
to be controlled. 

One type of rotary switch is composed of an arm ex¬ 
tending out from the center and which turns around 






Section 4 

68 ELECTRIC LIGHTING AND STARTING 


the center, being operated by a handle or button on 
the outside of the switch cover. This arm is made 
from copper or brass and is connected to one side of 
the battery line, either positive or negative. 

On the plate under this switch arm are arranged as 
many copper or brass rings as there are circuits to be 
taken care of, these rings being set one outside the 
other and all around the same center but insulated from 
each other. The arm makes contact with all the rings 
that are under it at any one time and, as the rings are 
connected through the lamps to the other side of the 


CIRCULAR CONTACTS 
r Circuit dosed by Pressing 
\ Any Part of Surface ^ 



PUSH BUTTON SWITCH FOR USE ON DASH LAMPS OR HORN. 


battery, the circuit is completed through the arm and 
ring and the lamps are lighted. In order that all the 
lamps may not be lighted at the same time and that they 
may all be turned of! these rings do not extend all the 
way around the circle, all of them having a rather wide 
gap at one point, where the ring is covered by insula¬ 
tion, and all of these gaps being arranged to come under 
the switch arm at the same time. This position would 
turn off all the lamps. As the arm is turned to another 
position it will make contact with the rings but if it is 
desired not to have the lamps lighted on some one cir¬ 
cuit the ring for this circuit is sunk away from under 











Section 4 

ELECTRIC LIGHTING AND STARTING 69 

% 

this position of the arm. By sinking the rings at the 
proper points any combination of lamps may be lighted 
at will. 

The knife switch is made with a thin piece of copper 



i, Push button switch, button pulled out closes contacts C-C through M; 
2 , Ordinary knife switch; 3 , Rotary switch; B, Wire from battery; H, head 
light ring with wire to lamps; S, Side light ring; R, Tail lamp ring; 
4, Rotary Switch using spring fingers in contact with segments set into 
insulating material. 

that can be pressed between two clips, the other end 
of the copper being pivoted for turning. 

The snap switch is the ordinary type of switch oper¬ 
ated by a turning button that is found in house lighting 
systems. Neither knife nor snap switches are used to 
any extent in automobile work. 

































HOW TO MAKE TESTS FOR LOCATING 
TROUBLES IN CAR WIRING. 

Tester. Every repairman should make a tester for 
use in locating electrical troubles. 

To make this tester secure three or four dry cells, 
not necessarily new ones, and fasten them to a board 
that is about two or three inches longer than neces¬ 
sary to accommodate the cells. To the extension of 
this board fasten an ammeter, a voltmeter or an elec¬ 
tric light socket. If the light socket is used place a 
bulb in it of the voltage of the number of dry cells used. 
Thus three dry cells would require a three-volt lamp. 
Now connect the cells in series, the positive terminal of 
one being connected to the negative terminal of the 
next one and so on. From the last unused terminal 
nearest the lamp or meter run a wire to one of the 
terminals of the lamp or meter. Then take two wires, 
each four feet long and insulated, and attach one of 
these wires to the remaining terminal of the lamp or 
meter and the other wire to the remaining terminal at 
the other end of the set of batteries. Cut the insulation 
from the free end of the two wires and bend these ends 
into loops and solder the loops so that the wire will 
not unravel. When these two loops are touched to¬ 
gether the lamp will light or the meter will show a 
flow of current. If one end of one wire is touched to 
any wire or metallic conductor and the other loop is 
touched to the other end of the same wire or conductor 
the lamp will light or the meter show a flow provided 

70 


ELECTRIC LIGHTING AND STARTINg“°71 

the conductor is not broken at any point between the 
two ends being touched. If one loop of the tester is 
touched to one end of a wire when the other end of that 
wire is grounded, the lamp should light or the meter 
show a flow when the other loop is touched to the 
metal of the ground. 



Connecting ends of wires (at A) causes lamp to light. Touching ends of 
tester wires to ends of defective wire indicates break (X) by lamp not 
burning. 

Broken or Loose Wires or Broken Circuits may De 

located with the tester by removing one end of the sus¬ 
pected wire from the terminal it is attached to and 
then touching each end of the wire with one of the 
tester loops. If the lamp does not light the wire is 
broken or there are loose connections in its length. 
















Section 4 

72 ELECTRIC LIGHTING AND STARTING 

It is absolutely necessary, in all tests, that the wire 
be removed from one end at the time of testing because 
if this is not done the current may return through an¬ 
other path. There will be cases where both ends of the 
wire need to be removed, as when grounds are to be 
located or when the wire divides into several parts. 

Tracing Circuits. In case it is desired to know just 
where a certain wire leads to, remove the end that you 
know and recognize, and attach it to one of the tester 
loops. Take the other loop of the tester and touch it in 
succession to other wire ends on the car until the lamp 
lights; you will then be touching the other end of the 
wire wanted. 

Locating Grounds, Short Circuits, Defective Insula¬ 
tion. Remove one end of the suspected wire from its 
terminal and attach it to the tester loop. Then touch 
the other loop to the metal of the car and of parts near 
which the wire runs, also touch it to all other wire 
terminals except the other end of the wire being tested. 
The lamp should not light under any of these condi¬ 
tions. If it does light examine the wire for the above 
troubles. 

A ground occurs when a wire touches the frame or 
a metal part so that the current can return to the bat¬ 
tery or to other wires or parts without going through 
the lamp or part that it should go through in order to 
do its work. 

A short circuit, usually called a “short,” occurs when 
one wire touches another wire so that current may re¬ 
turn to the battery without going to the lamp or part 
that it should go to in order to perform its work. Shorts 
may come at the ends of wires or at places where the 
insulation has been cut or chafed away. 


_ „ Section 4 

ELECTRIC LIGHTING AND STARTING 73 

In a single-wire system having fuses, or in any fused 
system, the line in trouble may be located by placing a 
lamp (not the tester but a separate lamp) between the 
terminals or clips that carry the fuse. If the lamp lights 
that circuit is shorted or grounded. 

Polarity of Wires and Reversed Connections. To 
find which of two wires carries positive or negative cur¬ 
rent place the bare ends in a glass of water in which 
has been dissolved a little salt or vinegar or any acid. 
The negative wire will bubble most. 

It is usually important that the positive wire be con¬ 
nected to one terminal and the negative to another ter¬ 
minal of a unit, these terminals being marked positive 
and negative. These connections must not be reversed. 
Places where it makes no difference how the wires are 
connected include the lamps and lamp sockets, knife, 
snap and push-button switches, the starting switch and 
the starting motor. 

The greatest care must be used to make sure that the 
positive wire from the dynamo is connected to the posi¬ 
tive wire of the battery and the negative dynamo wire 
to the negative of the battery. 

Connecting Ammeters and Voltmeters. Many sys¬ 
tems have ammeters installed and many more have 
not. Very few systems have voltmeters installed. In 
some cases it is a convenience to have a voltmeter so 
that the pressure of the battery charging current may 
be known. An ammeter, while not a necessity, tells 
the repairman and operator so many things regarding 
the operation, correct or incorrect, that one is very de¬ 
sirable in any system and may often be installed by 
the repairman to the great advantage of the system and 
the peace of mind of the driver. 

24 


Section 4 

74 ELECTRIC LIGHTING AND STARTING 

An ammeter may be mounted at any convenient point 
on the car. In using an ammeter for purposes of test¬ 
ing it is not necessary that it be solidly mounted at all; 
it may simply be laid anywhere while testing. 

After locating the ammeter (which must be made 
with zero at the center of the scale and readings both 
ways), go to the negative battery terminal and follow 
this wire in its path to the starting motor or starting 



METER CONNECTIONS. 
V, Voltmeter; A, Ammeter; C, Cut-out. 


switch. At some point between the starting motor 
and switch and the storage battery there will be a 
smaller wire leading from the large one. This smaller 
wire goes to the dynamo and lamps. If there is no 
starting motor it will not be necessary to look for the 
branch wire, the negative wire being run direct to the 
dynamo and lamps. Now follow this smaller wire, 
starting from the battery end, until it branches into 
two or more parts and stop there. You can cut this 


























ELECTRIC LIGHTING AND STARTINg“°75 

wire or break a connection at any point between the 
place where it leaves the starting circuit and the place 
where it branches. Cutting or breaking a connection 
will leave two free ends of wire. Now take a double 
wire or two wires and run one of them from one end 
of this break to one terminal of the ammeter and the 
other one from the other end of the break to the other 
ammeter terminal. 

Then turn on the lights with the engine idle and 
watch the ammeter. If the hand moves toward the 
side marked D or discharge your connections are right. 
If the hand moves toward the side of the dial marked 
C or charge you must reverse the wires at the ammeter 
terminals which will make it give the correct reading. 
If the dial of the ammeter is not marked place a D on 
the side of the ammeter toward which the hand moves 
when the lamps are turned on and on the other side 
place a C, indicating discharge and charge of the 
battery. 

If the connections are correct you can tape the joints 
made and fasten the wires to the car securely, finishing 
the job. 

One side of a voltmeter must be connected to the wire 
coming from the positive terminal of the dynamo be¬ 
fore this wire branches into two or more parts, the 
other voltmeter wire being connected to the negative 
terminal of the dynamo before its wire branches into 
two or more parts. This will cause the voltmeter to 
indicate the voltage of the dynamo when running but 
will prevent the battery current discharging through 
the voltmeter while the dynamo is idle because the cut¬ 
out is between the voltmeter connections and the 
battery. 


Section 4 

76 ELECTRIC LIGHTING AND STARTING 

Start the engine and watch the voltmeter hand and 
if no reading is secured the connections to the volt¬ 
meter terminals must be reversed. 

Ammeter or voltmeter hands should stand at zero 
when-the engine is idle and t»he lamps all off. If the 
hands do not stand at zero they may be adjusted by 
small screw or lever adjustments found around the 
outside of the case or by removing the front or back 
covers or plates. 


STORAGE BATTERIES. 


Action. A storage battery is a device for causing 
electric current to make certain chemical changes in 
metal plates and liquid contained in the battery jars. 
After the current makes this change the metal plates 
will cause a current of electricity to pass between them 
and this causes the plates to return to their original 
state. The battery may then be charged again by 
passing more current through it and so on. 



Six VOLT, THREE CELL STORAGE BATTERY HAVING 
REMOVABLE COVER. (WITHERBEE.) 

Construction. The ordinary batteries used in light¬ 
ing and starting systems are kno\yn as lead batteries. 
The plates are made from a composition of lead and 
antimony formed into a network, this part being called 
the grid. The grid has an extension at the top toward 
one side so that the current may pass into and out of 
the plate. 


































ELECTRIC LIGHTING AND STARTING^ 79 

This grid is full of a paste made from a mixture of 
red lead and litharge moistened with water and sul¬ 
phuric acid. This material is pasted into the grid and 
allowed to dry 

A mixture is then made of one-fourth pure sulphuric 
acid and three-fourths distilled water, this electrolyte 
liquid being placed in a glass, rubber or other insulat¬ 
ing jar. Several plates are then placed in the jar of 



INTERIOR OF A STORAGE BATTERY. 

Showing the plates and separators, the extensions on the top of the plates 
with the outside terminals and the space below the plates for sediment. 

electrolyte and the alternate plates are connected to¬ 
gether with the extension pieces at the top of each. This 
forms two sets of plates. There is always one more 
plate in one set than in the other set. 

In the bottom of the jars are ridges on which the 
plates rest so that a space is provided in the bottom of 
the jar for the collection of material that loosens from 
the plates and falls down. The plates are prevented 









Io ‘““electric lighting and starting 

from actually touching each other while in the jar by 
separators made from thin sheets of corrugated wood 
and thin sheets of hard rubber full of small holes. A 
cover is then placed over the top of the jar, this cover 
having a small hole in the center over each jar and this 
hole is closed by a screw plug having very small holes 
drilled through the plug. These plug holes allow the 
escape of gas while charging and discharging. 



SECTION THROUGH LEAD STORAGE BATTERY CELL SHOWING 
ARRANGEMENT OF PLATES AND SEPARATORS. 

The set of plates having the larger number is now 
connected to a wire carrying a negative direct current 
from a dynamo and the smaller set of plates is con¬ 
nected to a wire carrying positive direct current. 

The current is then allowed to flow through the cell 
from thirty-six hours to ten days at a very low am¬ 
perage. 

This slow charge changes the plates so that the set 
connected to the positive wire become covered with 


ELECTRIC LIGHTING AND STARTING*’”! 

peroxide of lead and turns a dark brown color and the 
plates connected to the negative wire are covered with 
spongy lead in a metallic form and are a dark gray color. 

The battery is then said to be charged and if the 
charging wires are removed and the terminals of the 
sets of plates connected by a wire there will be a flow 
of current between the plates and the battery will be¬ 
come discharged. 

Types. Storage batteries are used for ignition, 
lighting or engine starting. A starting battery will give 
satisfactory service for either ignition or lighting; a 
lighting battery will serve as an ignition but not as a 
starting battery and an ignition battery can not be used 
for either lighting or starting. 

Ignition service requires a flow from the battery of 
about one-half to one ampere and these batteries are 
made with a thick plate with hard material in the grid. 

Lighting service requires about five to ten amperes 
and these batteries are made with thinner plates so 
that the action of the acid electrolyte may more easily 
reach into the material and give the higher discharge 
rate. 

Starting batteries must give a discharge as high as 
125 amperes and to do this the plates are made very 
thin and the material is made quite soft or porous, mak¬ 
ing it possible to get very rapid action in the cell. 

The cranking ability of any system for starting the 
engine does not depend on the battery, it depends on 
the size and efficiency of the starting motor and its 
connections and gearing. 

Capacity. The amount of current that a storage bat¬ 
tery will hold is measured in ampere hours, this being 


Section 4 

82 ELECTRIC LIGHTING AND STARTING 

found by multiplying the ampere flow by the hours it 
takes to discharge the battery at that rate. 

Regardless of how large or how small a lead storage 
cell may be it will deliver a voltage of 1% to 2^4, no 
more and no less. The normal voltage of a single 
cell is two, regardless of the number or size of the 
plates of cell. 

When the cell is fully charged this voltage may rise 
to 2% and when the cell is discharged the voltage will 
fall to 1%. 

The ampere hour capacity of a cell however depends 
on its size, being governed by the cubic inches of ma¬ 
terial in the plates and the square' inches of plate sur¬ 
face exposed to the action of the electrolyte, the 
greater the cubic inches and surface the greater being 
the capacity of that cell. 

More current must be put into a cell than can be 
taken out. No cell could be 100 percent efficient any 
more than any other piece of machinery or device could 
have this efficiency. As a general rule from one-fifth 
to one-fourth more current must be passed into a stor¬ 
age battery than can be drawn out on the discharge. 

The temperature has a great deal to do with the effi¬ 
ciency and output of a battery. A battery will do its 
best work at about 70 degrees Fahrenheit. At 110 de¬ 
grees it will give 10 per cent more output than at 70 
degrees and at 20 degrees below zero it will give less 
than one-third its normal output. 

Electrolyte. As mentioned before the electrolyte or 
liquid in the cells is composed of one-fourth pure 
sulphuric acid and three-fourths distilled water. As the 
cell discharges, part of the acid seems to pass into the 
plates and the liquid then contains more water and 



' C « 2 

! 5 aJ v 

, 

I 4-» & 7^ 
^ CT3 2 

; G *** 

• ^ X 

>^ « o 

2 . 5 ^ 


















Section 4 

84 ELECTRIC LIGHTING AND STARTING 

less acid. The acid is nearly twice as heavy as the 
water so that the electrolyte becomes lighter as the 
cell becomes discharged. From this fact it is possible 
to gain a very good idea of the amount of current left 
in the battery by finding the weight of the electrolyte. 

The weight of the electrolyte is measured by float¬ 
ing a hydrometer in the electrolyte or by drawing 
some of the electrolyte out of the cell through the hole 
in the cover by means of a hydrometer syringe. This 



SIX VOLT STARTING AND LIGHTING BATTERY SHOWING 
TOP CONNECTIONS. 

is a syringe with a rubber bulb at one end and a small 
tube at the other and containing a hydrometer in the 
syringe. 

The stem of the hydrometer has numbers on it that 
run from 1,100 near the top to 1,350 near the bottom. 
The heavier the electrolyte is the higher the hydrom¬ 
eter will float and the number on the tube that is 
nearest the surface of the liquid indicates the weight 
or the specific gravity. 


ELECTRIC LIGHTING AND STARTING C “°85 

The battery may be tested at any time although the 
most reliable results are secured while it is being 
charged. Remove the plug from the top of the cell 
to be tested and stick the small tube of the hydrom¬ 
eter syringe down into the cell as far as it will go. 
Now squeeze the bulb and draw the electrolyte up 
into the syringe until the hydrometer floats in the 
liquid. Take the reading of the number nearest the 
surface and if this number is 1275 to 1325 the cell is 
fully charged. If it is 1200 it is half charged and if 



“LBA” LIGHTING AND STARTING BATTERY. 

it is as low as 1150 the cell is discharged and should 
be charged before further use. 

If the electrolyte is so low that the syringe will not 
draw it up, the cell must have distilled water added 
until the level of the electrolyte is three-eighths to 
one-half inch above the tops of the plates in the cell. 

Except under special conditions nothing except pure 
distilled water should be added to the cells of a stor¬ 
age battery. The acid does not evaporate and should 
not need replacing. If more acid is added the voltage 



Section 4 

86 ELECTRIC LIGHTING AND STARTING 

of the cell is temporarily increased but the life of the 
battery is shortened greatly. The less acid used in 



BATTERY TESTING HYDROMETER. 

The hydrometer itself is shown inside of the tube of the syringe. At the 
top is the rubber bulb and below is the long tube for reaching into the storage 
battery cell. 


a cell the longer the cell will last, but if the percentage 
of acid is too low the cell will give trouble through a 


















ELECTRIC LIGHTING AND STARTING C “°87 

deposit forming on the surfaces of the plates which pre¬ 
vents its proper action. 

Whenever the water gets low in the cells it must be 
replaced through the top filling plugs by more dis¬ 
tilled water or melted artificial ice or clean rain water 
collected in a wood pail. No water must ever be used 
from the pipes or taps or faucets in a city water sys¬ 
tem nor must any water be used from a metal con¬ 
tainer or from a spring. It will be necessary to re¬ 
place water lost by evaporation twice every month 
during cold weather and every week in hot weather. 
Fill each cell separately. 

In case part of the electrolyte is lost through spill¬ 
ing or leakage it will be necessary to replace this loss 
with a mixture of pure water and pure sulphuric acid 
made strong enough to give a specific gravity test the 
same as the electrolyte in the next cell. In mixing the 
electrolyte always pour the acid into the water and 
then let the mixture cool before using in the cell. 
Pouring water into acid will result in the acid being 
thrown out of the dish and sulphuric acid burns hands, 
clothes and everything else it comes in contact with. 

Should sulphuric acid or electrolyte be accidentally 
spilled on the hands or clothing apply a liberal quan¬ 
tity of strong ammonia immediately. The ammonia 
will neutralize the effects of the acid if applied soon 
enough. 

The terminals of storage batteries must be kept 
clean and bright in order that they may make good 
electrical contacts. The acid acting on the copper or 
brass terminals causes a deposit of green verdigris 
which does not allow the passage of current. This 
may be removed by washing with a solution made by 


ISOELECTRIC LIGHTING AND STARTING 

dissolving as much baking soda in hot water as the 
water will take up. After washing again with clean, 
pure water, dry the parts and cover them with a layer 
of vaseline everywhere except the parts that make ac¬ 
tual contact. 

Battery Charging. In actual operation in the car 
the battery is being charged all the time that the en¬ 
gine is running and it is being discharged all the time 
the lamps are lighted or the starting motor working 
or any other current consuming devices are in opera¬ 
tion. Thus the battery may apparently be charging 
and discharging at the same time. 

The actual operation of the system is that the dy¬ 
namo makes so much current, this current going either 
to the lamps or battery or part to each. When the 
lamps are of! all the current goes to the battery but 
when the lamps are turned on part of it goes to the 
lamps. If the lamps require all the current being made 
then none of it goes to the battery and should still 
more lamps be turned on so that the dynamo is not 
making enough current for them some additional cur¬ 
rent will be drawn from the battery to help out. When 
the lamps are turned on with the engine idle the bat¬ 
tery is being discharged only. Thus the battery acts 
as a kind of balance in the system between the dynamo 
and lamps, taking up any additional current not used 
and giving out extra current when needed. 

The state of charge of the battery may be found by 
testing the specific gravity of the electrolyte and if 
this is found to be below 1150 the engine should be 
run with the lamps turned off either with the car idle 
or running. When the battery is fully charged the 
electrolyte begins to bubble, these bubbles being 
hydrogen gas. 






















Section 4 

90 ELECTRIC LIGHTING AND STARTING * 

In order that a battery may be'maintained in good 
condition its specific gravity should never fall below 
1100 and should be kept above 1200 if possible. Every 
two weeks, whether the car be in use or laid up the 
engine should be run at a fair rate of speed until the 
specific gravity rises to at least 1275 and the cells give 
off gas. After the cells gas and the specific gravity 
does not rise any more continue to charge the battery 
by running the engine for one hour more. 

If a lead storage battery is allowed to stand for any 
length of time while discharged the plates become cov¬ 
ered with a thin coat of sulphate of lead and the bat¬ 
tery is said to be sulphated. This coating is an insula¬ 
tion between the plates and makes it hard to either 
charge the battery or use it for lighting or starting. 
To cure sulphating the battery must be removed from 
the car and charged at a very low rate, two or three 
amperes, for three or four days. Should this treatment 
fail to restore the battery it may be replaced in the car 
with the connections reversed, that is, connect the posi¬ 
tive dynamo wire to the negative battery terminal and 
the negative dynamo wire to the positive battery 
terminal. Now run the engine very slowly until the 
battery becomes completely discharged and the elec¬ 
trolyte tests nearly down to 1,000. The battery will 
then start to charge again but the terminal that was 
negative will then be positive and the positive terminal 
will be negative. Charge the battery in this direction 
until fully charged and then empty the old electrolyte 
out and replace with new liquid that tests 1275. Now 
change the connections back to the right way and re¬ 
charge the battery to its proper gravity. 

If the car is to be laid up the battery should be fully 


Section 4 

ELECTRIC LIGHTING AND STARTING 91 

charged by running the engine and then it should be 
recharged fully every two months while laid up. The 
better way is to remove the battery after it is* fully 
charged and send it to a battery company for storage. 

Should it be necessary to remove a storage battery 
from the car for charging it should be sent to a com¬ 
pany making a business of battery charging. 

If the battery must be charged in the shop it will 
first be necessary to have a supply of direct current or 
else make use of an alternating current line with a 
rectifier. 

If there is direct current in the building run a wire 
from the negative wire of the main supply line direct 
to the negative pole of the battery. Now extend a wire 
from the positive supply line and another from the 
positive terminal of the battery but do not connect 
these wires directly. Between these two positive 
wires place electric house lamps with one side of the 
lamp connected to one wire and the other side of the 
lamp to the other wire. Use three 32 c.p. carbon bulbs 
or six 16 c.p. or 50 watt carbon lamps between these 
two lines. Any combination of lamps may be placed 
between the battery and line positive wires that will 
give a flow of about three amperes. This is a very 
wasteful and expensive method of charging, costing 
from two to four times as much as it would cost to 
have the battery charged by a battery charging house. 

It is allowable to test the charge of a battery by 
using a voltmeter connected across the terminals for 
a few seconds. In doing this remember that each cell 
of the battery should give two or more volts; thus a 
three cell battery should give six to seven volts, a six 
cell battery from twelve to fourteen volts, etc. 


Section 4 

92 ELECTRIC LIGHTING AND STARTING 

Never connect an ammeter across the terminals of 
a battery under any conditions because the ammeter 
being of such low resistance will allow too great a flow, 
ruining the ammeter and possibly damaging the bat¬ 
tery. 

Never test a storage battery by touching the two 



BATTERY CHARGING. 

Through lamp resistance or through rectifier. 


terminals with the pliers or any other piece of metal 
as this damages the battery every time it is done. 

Gravity in one cell much lower than in the others, 
especially if successive readings show the difference 
to be increasing, indicates that the cell is not in good 
order. 

If one cell regularly requires more water than the 
others, thus lowering the specific gravity, a leaky jar 






























ELECTRIC LIGHTING AND STARTING*™ 93 

is indicated. Even a slow leak will rob a cell of all its 
electrolyte in time, therefore the leaky jar should be 
immediately replaced. 

If there is no leak and the gravity is, or becomes, 
fifty to seventy-five points below that in the other 
cells a partial short circuit or other trouble within the 
cell is indicated. This may be- caused by an excessive 
collection of sediment in the bottom of the jars, by 
metallic impurities added with the water, by buckled 
loose or broken plates. In any case the battery re¬ 
quires the attention of a shop equipped for assembling 
and disassembling batteries. 

A battery charge is complete when, with the charg¬ 
ing current flowing at the finishing rate (l/20th of 
the ampere hour capacity of the battery in amperes) 
all cells are bubbling freely and evenly and the specific 
gravity of all cells has shown no further rise during 
one hour. The gravity should test between 1.275 and 
1.300. 

The battery must be securely fastened in place in 
the car so that vibration and jar are avoided. The 
battery should rest on wood cleats and should have an 
air space all around it. The fastenings must take hold 
of the case or handles, not the terminals. 

The battery compartment must be kept clean and 
dry and tools and other small metal articles must be 
kept away from the battery. The terminals and con¬ 
nections should be kept coated with vaseline. 

Experience shows that about 90 per cent of storage 
battery trouble can be traced to one of two things: 
lack of filling with water and undercharging. Low 
level of the liquid causes ruined plates and excessive 
heating while charging. This is very harmful to the 
battery. 


^““ELECTRIC LIGHTING AND STARTING 

The commonest causes of undercharging are that 
the dynamo is not delivering sufficient amperage, there 
are loose wires or connections in the system or the 
dynamo commutator is in bad condition. 

The commonest cause of discharged batteries next 
to the above is that the operator is extravagant in 



INTERIOR OF LEAD STORAGE BATTERY. 

Showing the ridges on the bottom of the jar that form the sediment space. 
The arrow indicates the proper height of the liquid above the plates. 

using the current through burning lights needlessly 
and forcing the starter to do its work with the car¬ 
buretor improperly adjusted for easy starting. 

The other ten percent of troubles comes from broken 
jars and from short circuits or grounds in the wiring 
or lighting and starting units. In many cases it will be 






Section 4 

ELECTRIC LIGHTING AND STARTING 95 

found that the battery ignition switch has been left on 
with the engine idle. Broken jars invariably result 
from the battery not being properly fastened in place. 

Edison Storage Battery. The Edison battery is 
sometimes called the Alkaline Battery to distinguish 
it from the Acid Battery. The materials used in its 
construction are entirely different from the lead cell 
although both types are made up of plates, separators, 
jars and electrolyte. 

The positive plates are made from a nickel steel grid 
which holds a number of nickel plated steel tubes ver¬ 
tically, these tubes being filled with alternate layers of 
nickel hydrate (green) and pure flake nickel. There 
are 350 of these layers to each inch of tube. The neg¬ 
ative plate is formed of a nickel plated steel grid hav¬ 
ing pockets filled with an iron oxide and a small per¬ 
centage of mercury to increase the conductivity. 

The positive plates are assembled in one group and 
the negatives in another group, there being one more 
negative plate than positive in each cell. 

These plates are kept from actual contact by hard 
rubber rods placed vertically between the positive and 
negative, the plates alternating in polarity through the 
cell. The set of plates rests on a hard rubber frame 
on the bottom of the container, being held about one- 
half inch from the bottom. 

The positive and negative plates, assembled, are 
placed in a nickel plated steel jar and the top of the jar 
is welded on. There is a hole in the cover which is 
closed by a hinged cap, the cap carrying a check valve 
that opens outward only, this being for the escape of 
gas. By lifting the hinged cap the cell is filled with 
the electrolyte to a point one-half inch above the tops 
of the plates. 


Section 4 

96 ELECTRIC LIGHTING AND STARTING 


The electrolyte is composed of pure distilled water 
with 21 per cent of potassium hydrate (caustic potash) 
and a small quantity of lithium hydrate. The specific 
gravity of this electrolyte when new is 1.250 and this 
gravity remains practically constant for long periods 
of time. The gravity does not change with the charge 
and discharge but will finally fall to 1.150 after one 
to two years’ use when it is replaced with fresh 
solution. 



EDISON BATTERY PLATES, POSITIVE BEING IN FRONT 
OF THE NEGATIVE. 


As the battery is charged the iron oxide in the neg¬ 
ative plate is changed to metallic iron and the nickel 
hydrate in the positive plate is changed to black nickel 
oxide. The oxygen passes from the iron to the nickel 
and on the discharge the process and changes are re¬ 
versed. 

The voltage of each cell of this type of battery is 
1 2/10ths, the six volt battery having five cells, the 
twelve volt having ten cells, etc. 













ELECTRIC LIGHTING AND STARTING*^}. 

The Edison battery is about half the weight of a 
lead battery having the same capacity and it is not 
damaged by vibration, overcharge, idleness' without 
attention or short circuiting. No sediment forms in 
the jars, making it unnecessary to take them apart for 
cleaning. 



EDISON BATTERY PLATES ASSEMBLED READY TO BE PLACED 
IN CONTAINER TO FORM ONE CELL. 

This battery is charged at an ampere rate repre¬ 
senting one-fifth of the ampere hour capacity of the 
battery and the discharge rate is the same as the charg¬ 
ing rate (normal). Frothing of the electrolyte indi¬ 
cates that there has been sufficient rate of charge. The 
voltage of the battery indicates the state of charge. 




^“""ELECTRIC LIGHTING AND STARTING 

It is necessary to give the battery 1 2/5ths times the 
charge in ampere hours that is drawn out of it. That 
is, for every 100 ampere hours drawn from the battery 
140 ampere hours charge must be given. The dis¬ 
charge rate should be the same as the normal charge 
(one-fifth the ampere hour capacity) but in any case 



SECTION THROUGH EDISON BATTERY CELL. 

it should not exceed this rate by more than twenty-five 
per cent on the average. 

The voltage of the charging current should be at 
least 1% times the voltage of the battery on discharge. 

The battery will stand a heavy overcharge, being 
capable of taking a charge for five minutes at five times 



















ELECTRIC LIGHTING AND STARTING Ct '°99 

the normal rate, for fifteen minutes at four times the 
normal rate, for thirty minutes at three times the nor¬ 
mal rate and for one hour at twice the normal rate. 
The cells should be kept filled with pure distilled 


METHOD OF TESTING HEIGHT OF SOLUTION ABOVE PLATES 
IN EDISON STORAGE BATTERY. 



RUBBER 
TUBING - 


£GLASS 

tube: 


water to a point one-half inch above the tops of the 
plates and any spilled or lost electrolyte (except that 
lost through evaporation) should be replaced with 
Standard Renewal Solution manufactured by the Edi¬ 
son Storage Battery Company. Never use acid or any 











Section 4 

100 ELECTRIC LIGHTING AND STARTING 

articles that have been used around a lead battery. 
Flame should be kept away from the battery cell caps. 

After long use the specific gravity of the electrolyte 
will fall to 1.150 and at this point it should be poured 
out of the battery and replaced with new Standard 
Renewal Solution. Pour about half the liquid out, 



F.DISON LIGHTING BATTERY. 


shake the remainder well and empty the cell com¬ 
pletely. Before doing this the battery should be fully 
discharged by short circuiting it for about half an hour. 
The electrolyte will freeze solid only when the interior 
of the battery reaches a temperature of 24 degrees be¬ 
low zero. 



THE CUT-OUT. 


There are three general divisions into which the 
various forms of cut-outs may be divided. These in¬ 
clude hand operated, centrifugally operated and elec- 
tro-magnetically operated forms. 

Hand Operated. This is the simplest form in use, 
being simply a switch that completes the circuit be-^ 
tween the motor-generator and battery, and the igni¬ 
tion parts with the same motion. This also forms the 
starting switch. 

In this system a dynamo and motor are combined in 
one unit and connected positively td the engine without 
the use of overrunning clutches. The gear reduction 
must therefore be low and for two reasons the motor- 
generator must be of large size. 

One of these reasons is that, having a low reduction 
the motor must be powerful in order to start the en¬ 
gine. The other reason follows : 

When the combined switch is closed the current is 
sent from the battery to the dynamo and as the battery 
current is of higher voltage (the dynamo standing still) 
the dynamo acts as a motor and starts the engine spin¬ 
ning. The same switch has a connection that turns on 
the ignition when it starts the motor so that the engine 
immediately begins to fire and run on its own power. 
The switch is left closed while running. 

The dynamo being of such large size it generates a 
higher voltage than the battery just as soon as the 
gasoline engine starts running and at any speed at 

101 


foTELECTRIC LIGHTING AND STARTING 

which the gasoline vapor will ignite (and run the en¬ 
gine) the dynamo makes a voltage higher than that of 
the battery. 

This higher voltage of the dynamo prevents the bat¬ 
tery from discharging through the dynamo and causes 
the current to flow from the dynamo to the battery 
performing the work of charging as long as the engine 
runs. 

To stop the engine the switch is simply opened which 



HAND OPERATED CUT-OUT. 


stops the ignition and breaks the connection between 
the dynamo and battery preventing battery discharge. 

Should the engine cease to fire or stall, the dynamo, 
being connected to the battery, immediately acts as a 
motor again and starts the engine or else turns the 
engine and drives the car with the power of the elec¬ 
tric motor. 

Centrifugal Types. When a weight is whirled 
around a point the weight tries to fly out and away 












Section 4 

ELECTRIC LIGHTING AND STARTING 103 

from the point. The faster it whirls the harder the 
weight pulls. This force or pull is called centrifugal 
force. 

(1) Centrifugal governors such as are used in cut¬ 
outs are usually made with two small weights carried 
on short arms, these arms being pivoted to a revolving 
shaft such as the armature shaft. The weights are held 



CENTRIFUGAL GOVERNOR CUT-OUT. 

D, Dynamo; C, Cut-out contact points; W, Governor weights; P, Sliding 
block and lever operating contacts. 

close to the shaft by springs, but as the speed of the 
shaft increases, the power of the springs is overcome 
by centrifugal force and the weights move out from 
the shaft and cause the arms to move. These arms 
are connected with some form of lever which moves 
farther and farther the faster the shaft turns and the 
more the weights pull out. 

















Section 4 

104 ELECTRIC LIGHTING AND STARTING 

This moving lever or rod operates a switch which 
connects the battery with the dynamo. When the 
shaft is idle with the dynamo standing still the weights 
are close to the shaft and the switch is open. As the 
speed increases to a point where the voltage of* the 
dynamo becomes higher than that of the battery 
the movement of the governor closes the switch and 
the dynamo charges the battery. 

(2) Another form of centrifugal cut-out switch is 
called the mercury type. It is composed of a hollow 
cylinder with the outside divicfed into a number of sec¬ 
tions and insulated, from each other. The ends are 
closed with insulating material and inside the cylinder 
is placed a small quantity of mercury. The cylinder 
is attached to a moving part of the dynamo. Brushes 
are placed in contact with each side of the cylinder, the 
brushes being ;directly opposite each other, one being 
connected to the dynamo and the other to the battery. 
With the cylinder idle no current can pass from one 
brush to the other through the cylinder on account of 
the insulation between the sections. As soon as the 
dynamo revolves the cylinder the mercury spreads 
around the inside of the cylinder completing the con¬ 
nection between the sections and the two brushes. The 
amount of mercury is made such that it completes the 
circuit when the dynamo voltage has become greater 
than that of the battery and charging takes place. 

(3) There is another form of sectioned cylinder with 
brushes, but in place of-having mercury inside the cyl¬ 
inder there is a set of weights held away from the in¬ 
side of the cylinder by springs. As the speed of the 
cylinder increases the weights fly out and complete 
the connection. 


ELECTRIC LIGHTING AND STARTING'To5 

Electro-Magnet Operated Types. Before consider¬ 
ing this type some of the principles on which electro¬ 
magnets operate should be clearly fixed in mind. 

If an electro-magnet is connected in series in any 
line, that is, if the line or wire is cut and the two ends 
of the magnet winding are attached to the cut ends, 
this magnet will get stronger and stronger as the flow 
of amperes in this line increases. This is called a series 
electro-magnet and is said to operate by amperage. 



ELECTRO- MAGNETIC CUT-OUT. 


If an electro-magnet is connected in any circuit as 
a shunt so that the main flow of current passes by the 
magnet and only part of it flows through the magnet 
this magnet will get stronger and stronger in its pull 
as the voltage in the lines increases. It is called a shunt 
electro-magnet and operates on voltage. 

.When a piece of iron or steel is placed close to the 
end of an electro-magnet it will be pulled toward the 
magnet when there is a flow of current through the 

magnet. If this piece (called the magnet armature) is 
26 




Section 4 

106 ELECTRIC LIGHTING AND STARTING 

held away from the end of the magnet by a spring the 
armature will not move toward the magnet until the 
pull in the magnet caused by the increase in amperage 
or voltage is great enough to overcome the action of 
this spring. The tighter the spring tension the 
greater will the amperage or voltage have to be to 
overcome it. 

The windings on an electro-magnet may all run one 
way or they may be in two parts, running opposite 
ways forming a bucking coil so that one winding tends 
to make the magnet strong but the other winding tends 
to destroy the magnetism and weaken the magnet. This 
forms a differential electro-magnet. 

(1) The simplest form of electro-magnetic cut-out 
is arranged as follows: There is a plain electro-magnet 
connected in shunt, with its armature held away by a 
spring that requires a pull from the magnet, caused by 
a voltage higher than that of the battery. 

The wire from the battery is led to one platinum con¬ 
tact of the cut-out mounted on the magnet armature or 
stationary. The dynamo wire is carried on another 
platinum contact arranged so that when the armature 
touches the magnet these contacts are brought to¬ 
gether. 

When the voltage from the dynamo rises above the 
battery voltage the armature is pulled to the magnet 
against the action of the spring, closing the contacts 
between the dynamo and battery and allowing charg¬ 
ing to commence. As soon as the dynamo speed falls 
so low that its voltage is less than the battery the 
spring opens the cut-out, preventing battery discharge 
through the dynamo. 




_ _ Section 4 

ELECTRIC LIGHTING AND STARTING 107 



ELECTROMAGNETIC CUT-OUTS 


i, Simple shunt connected coil; 2, Compound wound coil on magnet; 3, 
Current ordinarily passes through closed contacts (A) to shunt magnet coil, 
closing the cut-out contacts (C) and opening (A), forcing ^he magnet cur¬ 
rent through resistance coil (R). 













































































Section 4 

108 ELECTRIC LIGHTING AND STARTING 

(2) A variation of this type has two windings on 
the magnet, both running the same way and acting to¬ 
gether. One winding is connected in shunt so that when 
the voltage rises high enough the cut-out closes and 
completes the circuit for charging. This charging cur¬ 
rent flows through the other winding, making the mag¬ 
net hold its armature even tighter. Should the voltage 
of the dynamo fall below that of the battery the current 
starts back through this second winding in the opposite 
direction- from the battery to the dynamo. Just as the 
voltage changes there is no flow and the. magnet re¬ 
leases its hold and the contacts open. A momentary 
reverse flow causes the second winding to buck the 
shunt so that their power is completely destroyed, al¬ 
lowing the spring to easily open the contacts. 

(3) One form of electro-magnet cut-out has two sep¬ 
arate electro-magnets mounted end to end and one 
above the other. The lower one is hinged so that it 
can fall away from the top one which is stationary. 
There are arms attached to the two magnets carrying 
platinum contacts that close the circuit between the 
battery and dynamo for charging. The upper coil is 
connected in shunt and when the voltage rises it at- 
tract$ the lower coil to it, closing the circuit. The 
charging current then flows through the lower coil, 
which is in series, causing them to hold tight together 
until the voltage drops. As the current starts to re¬ 
verse and flow backward through the lower magnet its 
polarity is reversed and it repels the upper magnet, 
opening the circuit. 

(4) Still another form is arranged so that when the 
charging contacts come together another set of con- 


Section 4 

ELECTRIC LIGHTING AND STARTING 109 

tacts open. When this second set is open or apart the 
current flows through resistance wire before reaching 
the electro-magnet coil. When these extra contacts 
are touching, the current to the electro-magnet coil 
flows through them in place of through the resistance, 
making the magnet pull its armature toward it. As the 
armature touches the magnet and completes the charg¬ 
ing circuit the second contacts open and the current 
flowing to the coil through the resistance lowers the 
holding power of the magnet on the armature to a point 
such that the charging contacts are easily opened by a 
light spring when the current starts to reverse. 

Cut-Out Indicators. Whenever the cut-out charging 
contacts are closed the battery is supposed to be un¬ 
dergoing charge from the dynamo, or, even if not being 
charged, the dynamo voltage is high enough to prevent 
discharge of the battery. If an ammeter is connected 
to the battery it will show a charge at this time, pro- 



AMMETER FOR USE TN LIGHTING AND CHARGING CIRCUIT. 
Showing adjustment at lower part of front cover. 





Section 4 

110 ELECTRIC LIGHTING AND STARTING 

vided too many lamps are not turned on, thus serving 
to tell the driver that the battery is being properly 
charged, or, with the engine running fairly fast, if the 
ammeter does not show charge then the driver may 
know the dynamo is not generating or that there is a 
broken or loose connection somewhere. 

Some cars that do not have an ammeter have an ex¬ 
tension moving with the armature attracted by the 
magnet. This extension has the letters C and O on it. 
When the cut-out is closed the letter C appears through 
a little glass window, indicating a charge, and when 
the contacts are open the letter O appears, indicating 
off. 

Other systems have a small electric lamp arranged 
so that it is turned on when the cut-out is closed'. 
This lamp is on the dash and whenever it is burning 
the battery is being charged. 

Cut-Out Regulation. The cut-out should close the 
contact between the battery and dynamo just as soon 
as the voltage is high enough to charge the battery. 
This is usually almost as soon as the engine starts to 
run. The spring tension should be lessened or other 
regulating device adjusted so that the cut-out closes 
quicker and quicker, that is, at lower and lower car 
speeds until a point is reached where the ammeter 
shows a discharge when the cut-out closes, indicating 
that the dynamo voltage is not high enough. The ad¬ 
justment may then be set back a very little to prevent 
this discharge. 

The cut-out is supposed to be closed at all times dur¬ 
ing which the car is being run at average speed. If 


Section 4 

ELECTRIC.LIGHTING AND STARTING 111 

the average driving speed is twelve miles per hour then 
the cut-out should be closed at a speed a little below 
twelve miles per hour, otherwise the car will be driven 
most of the time without charging the battery. 

Hand-operated cut-outs have no adjustment, lessen¬ 
ing spring tension on others, charges the battery at a 
lower speed. 


CURRENT OUTPUT REGULATION. 


There are two qualities of an electric current that re¬ 
quire to be controlled or regulated for the successful 
charging of storage batteries and lighting of lamps. 
One of these qualities is the voltage or pressure, the 
other being the flow or amperage. In some of the early 
forms voltage regulators were installed in the form of 
resistance units operated by a sliding switch with a 
centrifugal governor, inserting more resistance as the 
speed and voltage of the dynamo increased and in this 
way preventing too high a voltage in the lighting 
lines. 

It is a fortunate fact, however, that when a storage 
battery is carried on the lines between the dynamo and 
the battery this battery acts as a very efficient voltage 
regulator. If a six-volt battery is connected on the 
lines so that the negative terminals of the dynamo, bat¬ 
tery and lamps are all fastened together and the posi¬ 
tive terminals of the three units are all fastened to¬ 
gether the voltage in the whole system outside of the 
dynamo will not rise above the voltage of the battery, 
practically six volts being maintained at all times 
throughout the system. If the battery is a twelve- 
volt unit the voltage will be maintained at twelve 
throughout the system and so on. 

The actual voltage and amperage made and delivered 
by the dynamo become greater the more speed the dy¬ 
namo runs at and decrease as the speed falls. The 
amperage delivered to a lead battery must not rise 
above one-eighth of the battery capacity in ampere 
112 


ELECTRIC LIGHTING AND STARTING^m 

hours, the charging rate being measured in amperes. 
The dynamo being run from the engine and the en¬ 
gine running at speeds from 250 to 2500 revolutions a 
minute in ordinary use it is evident that some means 
must be provided for preventing excessive charging 
rates. 

There are more than a dozen ways of accomplishing 
this and there are fully a dozen variations of some of 
these methods. Luckily but a very few methods are 
actually in use so that the repairman can easily be¬ 
come familiar with the principles of operation of the 
ones commonly found and with their principal vari¬ 
ations. 

The output of a generator in amperes may be limited 
by causing electro-magnets to change some condition 
of operation, by other electrical means or by mechanical 
means. Methods that affect the magnetic lines of force 
from the fields include means for increasing or decreas¬ 
ing the flow of current around the fields, using com¬ 
pound or differential field windings, by using such a 
small field core that it will not increase its strength 
above a certain point, by using additional brushes be¬ 
tween the regular collecting brushes that cut off part 
of the lines of force, by having extra field poles between 
the regular poles that pull the lines of force to one side 
or by making it possible to rotate the fields around the 
armature slightly while the brushes remain stationary. 
These methods take advantage of the fact that an in¬ 
crease or decrease in the field strength causes an imme¬ 
diate increase or decrease in the output of the dynamo. 

Mechanical control may be effected by causing 
breakers to induce currents to flow through the fields 
in a reverse direction, by moving the pole pieces from 


Section 4 

114 ELECTRIC LIGHTING AND STARTING 

between the magnet poles and armature core leaving a 
greater air gap, by operating the dynamo at a steady 
speed or by operating the dynamo from a steady and 
constant force or power. 

Practically all means of regulation in use increase 
or decrease the strength of the currents flowing around 
the field coils and consequently affect the strength of 
the magnetic fields (this type including differential 
windings or bucking coils) or else they drive the gen¬ 
erator at a constant speed. Other methods are used 
in rare cases. 

Many variations and combinations of the above types 



CONTROLLER AND CUT-OUT (LEFT) AND DYNAMO (RIGHT). 


of control are used but these principles cover all cases. 
The regulating systems may be grouped as follows: 

I. Changing the field current and strength. 

(1) Varying resistance in field windings. 

(2) Controlled compound field windings. 

(3) Controlled bucking coil field windings. 

(4) Using a large field winding and small core. 

(5) Extra brush machines. 

(6) Extra magnetic pole machines. 

(7) Rotating the fields to a new position. 

(8) Permanent magnets with field windings. 

II. Mechanical or semi-mechanical control. 




ELECTRIC LIGHTING AND STARTING*"115 

(1) Constant armature speed. 

(2) Constant power driving armature. 

(3) Reverse field currents induced by breaker. 

(4) Movable pole pieces or movable armature 

position. 

All forms of current output regulation take it for 
granted that the dynamo is capable of generating a 
flow in amperes that is too great for the work of bat¬ 
tery charging and lamp lighting. 

Means are always provided for decreasing the output 



OUTPUT CONTROL, SHUNT FIELD RESISTANCE. 
(Ward Leonard Type.) 


when it becomes too great but very little provision has 
been made for increasing the output when it is too little. 

Actual observation usually fails to discover batteries 
damaged by overcharging but this same observation 
shows hundreds of batteries injured or ruined by under¬ 
charging. Undercharging of the battery is in many 

















































Section 4 

116 ELECTRIC LIGHTING AND STARTING 

cases the fault of the driver through ignorance or neg¬ 
lect. It being impossible to educate the whole number 
of users of these systems (numbering hundred of thou¬ 
sands) in their proper operation and care the only thing 
remaining is to provide means for better and mQre bat¬ 
tery charging and in adopting means for forcing the 
proper care of batteries, especially in the replenishment 
of water. This will have to be taken care of in some 
way to insure the success of these systems. 

The greatest single trouble encountered by repair¬ 
men is that of discharged batteries. 

Varying the Shunt Field Current. The shunt field 
winding has one end fastened to one of the brushes, the 
other end leading to a resistance of some kind. Ar¬ 
rangements are made for inserting this resistance in 
the shunt field circuit before its return to the other 
brush, or for cutting this resistance out of the circuit 
and allowing the current to return directly to the other 
brush. Many forms of resistance are used and there 
are many methods of varying or controlling this re¬ 
sistance. 

(1) One well known system using this type of con¬ 
trol is the Ward-Leonard. In this system there is a 
small coil of ,high resistance wire in a case on the dash 
together with a series connected electro-magnet in the 
main charging circuit. This magnet increases its pull 
as the amperage in the charging line increases and this 
increased pull draws a magnet armature toward the 
magnet. This armature carries one platinum contact 
which is connected to one end of the shunt field wind¬ 
ing and when the armature is away from the magnet 
this contact touches another contact which is connected 
to the brush on the commutator. This allows the cur- 


ELECTRIC LIGHTING AND STARTING''117 

rent to return from the shunt field to the brush through 
the platinum contacts but when the current increases 
enough to pull the armature, these contacts are sep¬ 
arated. When they are apart the field current must 
return through the resistance coil; this reduces the 
strength of the field and the output of the dynamo. The 



CONTROLLER AND CUT-OUT. (Ward Leonard.) 

A-B, Coil and core of magnet for the cut-out, having both shunt and 
series windings; C, Moving arm attracted by magnet and carrying con¬ 
tact; D-D, Cut-out contacts which close charging circuit; E-E, Regulator con¬ 
tacts which close normally to complete the shunt field current without any 
resistance; F-G, Coil and core of regulator magnet, carrying winding in 
series with charging of battery; H, Moving arm of controller which opens 
contacts (E-E) when attracted by magnet with increase in charging current; 
J, Spring for holding contacts (E-E) closed; K, Spring for holding cut-out 
contacts open; L, Series coil location in cut-out magnet; M, Resistance in¬ 
serted in shunt field circuit when contacts (E-E) are opened by magnet (F). 


lessened output passing through the electro-magnet 
lessens its pull and a small spring pulls the contacts 
together again, cutting out the resistance and allowing 
the output to increase. In operation the armature vi¬ 
brates continually, opening and closing the contacts 
rapidly. Increasing the spring tension increases the 
output of the dynamo. 
















COMPLETE WIRING DIAGRAM OF TYPICAL (ADLAKE) LIGHTING 
SYSTEM SHOWING INTERNAL WIRING OF REGULATOR, 
CUT-OUT AND LIGHTING SWITCHES. 







































































































. Section 4 

ELECTRIC LIGHTING AND STARTING 119 


(2) Another form is composed of a solenoid with a 
movable plunger. This plunger is supported in the 
solenoid by one end of a small chain, this chain passing 
over a pulley and being balanced at the other end by 
a small container holding small lead shot. This pulley 



REGULATOR USING A SOLENOID WITH MOVABLE PLUNGER 
OPERATING A RHEOSTAT. CUT-OUT IS CON¬ 
TAINED IN SAME CASE. 

carries a movable arm that is connected to one end of 
the shunt field winding and makes contact with various 
points on a rheostat so that movement of the arm down¬ 
ward when the pulley moves increases the resistance in 












Section 4 , 

120 ELECTRIC? LIGHTING AND STARTING 

the field winding. As the charging current (passing 
through the solenoid) increases, the solenoid pulls the 
plunger deeper and deeper into the coil. This lowers the 
rheostat arm, increasing the shunt field resistance and 
lowering the output. 

(3) Still another form uses a number of carbon discs 
loosely piled on each other. One end of the field wind- 



OUTPUT CONTROL, SHUNT FIELD RESISTANCE. 

C, Carbon disc pile; S, Spring holding discs together; M, Magnet in 
series with battery; A, End of arm pulled by magnet, releasing tension on 
discs. 

ing is attached to the upper carbon disc, the lower disc 
being connected to the dynamo brush. When these 
discs are loose upon each other their resistance is high 
but they are held tight together by a pivoted arm across 
the top which holds them down, the arm being pivoted 
and forced down by a spring. The arm rests on the 












































ELECTRIC LIGHTING AND STARTING*'121 

discs. Near the arm is an electro-magnet that carries 
the charging current and as the amperage of the charg¬ 
ing current increases this magnet pulls on the arm 
against the spring action and releases some of the pres¬ 
sure on the discs. This increases the resistance in the 
shunt field and lowers the output. Lowering the out¬ 
put decreases the pull of the electro-magnet and the 
discs are pressed tighter together, reducing the resist¬ 
ance and increasing the output. Increasing the spring 
tension increases the output. 

(4) Some forms use several windings on an electro¬ 
magnet or solenoid, these windings causing the magnet 
or solenoid to hold resistance in the shunt field circuit. 
Turning on more lamps cuts out some of these windings 
so that all the resistance is not held in the circuit, in¬ 
creasing the output to take care of the additional load. 

Controlling the Armature Position. This system is 
not used in this country. As the speed increases the 
output, the additional strength of an electro-magnet 
pulls the armature endwise out of the field against the 
action of a spring. All of the lines of force do not go 
through the armature and the output is lessened. 

Controlling Pole Piece Position. This system is 
not much used in automobile work at present. The 
pole pieces are slid out from between the armature and 
field magnets increasing the air gap that the lines of 
force have to travel and thus lowering the output. 

Compound Field Windings. One system of com¬ 
pound windings is connected so that only the. current 
for the lamps passes through the series winding. This 
additional current increases the power of the magnets 
and makes the field stronger. 

Compound winding tends to maintain a uniform out¬ 
put. 

u\ 


Section 4 

122 ELECTRIC LIGHTING AND STARTING 



OUTPUT CONTROL, BUCKING COILS. 

Upper—Bosch-Rushmore system : R, Ballast coil; Sh, Shunt winding; 
Se, Series bucking coil. 

Lower—Bucking coil controlled through lamp circuit; S, light switch; 
Sh, Shunt field; Se, Bucking coil field. 































































ELECTRIC LIGHTING AND STARTING** 123 

Bucking Field Coils. One system, the Bosch-Rush- 
more, has the series coil bucking the shunt. No cur- 



A MOTOR-GENERATOR CONTROLLER. 

Showing the electro-magnetic cut-out and the starting switch, the regulator 
being on the opposite side. i, Starting switch contact; 2, Arm to hold cut¬ 
out open while starting; 3, Button to operate (2) when starting switch closes; 
4-5, Cut-out contact points; 6-7, Starting switch lever; 8, Cut-out bracket; 
9, Starting switch contact; 10, Starting switch spring; 11, Switch spring arm; 
12-13, Cut-out contacts; 14, Arm or stop for contacts; 15, Cut-out magnet 
armature; 16, Cut-out armature spring. 


rent passes through the series coil under ordinary 
conditions, the current that would ordinarily pass 























Section 4 

124 ELECTRIC LIGHTING AND STARTING 


through this coil going to the battery and lamps 
through a small coil of iron wire mounted on the dash 



A MOTOR-GENERATOR CONTROLLER. 

Showing the electro-magnetic regulator, the cut-out and starting switch 
being on the opposite side. 21, Regulator bracket; 22-23, Contacts opened and 
closed by regulator electro-magnet and through which the bucking coil is 
controlled. When contacts are open current is forced through bucking coil, 
lowering output; 24, Regulator bracket; 25, Shunt field winding contact, 
closed except when acting as starting motor; 26, Regulator spring; 27, Regu¬ 
lator adjusting screw, turning in decreases output; 28, Regulator electro¬ 
magnet armature; 29, Regulator spring; 30, Shunt winding contacts, same 
as (25); 31, Regulator armature stop. 


board. In other words, this iron wire (ballast coil) is 
connected in shunt with the series coil. A peculiar 
property of iron wire is that it carries a certain amper- 















ELECTRIC LIGHTING AND STARTIN(fl25 

age without increase in its resistance but at any higher 
amperage the iron becomes red hot and the resistance 
increases to a point, that practically prevents further 
passage of current through the iron. The current then 
passes through the series coil, bucking the shunt and 
lowering the output so that the iron wire cools off. 

(2) Another type makes use of permanent magnets 
with a shunt winding and a bucking series coil on the 
permanent magnets. At slow speeds the shunt wind¬ 
ing assists the permanent magnets but as the dynamo 
goes faster the shunt winding is cut out by an electro¬ 
magnet. When the speed increases still more the cur- 



CONSTANT ARMATURE SPEED CONTROL OF DYNAMO. 

Showing a slipping plate clutch with its centrifugal governor weights' and 
spring. (Gray & Davis.) 

rent flows through the bucking coil but with a resist¬ 
ance coil in series with the bucking coil so that only a 
little current bucks the permanent magnet. At the 
highest speeds the resistance is cut out, allowing the 
full strength of the bucking coil to oppose the perma¬ 
nent magnets. 

(3) Still another system uses a bucking coil con¬ 
nected in such a way that the current flows to the 
battery through the bucking coil when the lamps are 
turned off. When lamps are turned on the current flows 





























Section 4 

126 ELECTRIC LIGHTING AND STARTING 

to the lamps in place of to the bucking coils so that the 
reduction of force in the bucking coils increases the 
output to take care of the lamps. 

Large Field Coil and Small Core. The strength of 
magnetism in an electro-magnet increases as the cur-, 
rent in the winding increases. This is true up to a 
certain point at which the iron becomes saturated with 
magnetism and can become no stronger regardless of 
the increase of strength in the field coils. This only 
happens when the coils are extremely large compared 
to the core of the magnet. The core becomes saturated 
at the point of amperage desired as a limit, so that the 
field can not increase its strength nor the output of the 
dynamo past this point. 

Extra Brush Machines. This system has a second 
brush or set of brushes between the regular set. These 
extra brushes connect with another set of fields and 
field windings through a resistance. When the current 
in these secondary brushes overcomes the resistance 
the extra poles are magnetized and these overcome part 
of the effect of the regular poles. 

Extra Pole Machines. There are extra poles between 
the regular ones, these extra poles having no windings. 
Above a certain speed the lines of force pass into these 
extra poles in place of entirely through the armature 
so that their whole effect does not induce currents in 
the armature and the output is lowered. 

Rotating the Fields. The fields are arranged to turn 
around the armature, being pulled by a governor 
against the action of a spring. The brushes remain 
stationary so that they do not collect the current just 
as the armature windings are changing through the 


Section 4 

ELECTRIC LIGHTING AND STARTING 127 

lines of force but a little before or after this position. 
This prevents the brushes from collecting the current 
at its highest value and the output is lowered. 

Constant Armature Speed. This is accomplished by- 
having the armature driven from the engine through a 
friction clutch. This clutch is held in engagement by 
springs but when the speed reaches a point at which the- 
output is at its safe linfit these springs are overcome 
by centrifugal governor weights and the clutch is re¬ 
leased so that the speed and output cannot increase 
beyond this point. 

Constant Driving Power. The varying power and 
speed of the engine make this system unsuitable for this 
kind of work. 

Reversed Field Currents. If the current flowing 
through a field winding be broken there is an extra 
current induced in the fields that flows the same way 
as the regular current, but, when the current is made 
again there is an induced current flowing the opposite 
way and opposing the regular winding. A mechanical 
vibrator or breaker operates above a certain speed pro¬ 
ducing these reversed currents and lowering the output. 

The systems that the repairman will encounter in¬ 
clude the varying field currents produced in various 
ways, constant speed types, bucking coils and extra 
brush machines. The other systems are not found in 
common use, being given simply for completeness and 
reference. 


STARTING MOTORS. 


Requirements. To start the average automobile en¬ 
gine requires a starting motor being able to deliver 
power from one-half to one horsepower. 

This starting motor must be able to turn the engine 
crankshaft at a speed from 50 to 125 revolutions per 
minute in order to start the engine with good carbu- 



SMALL HIGH POWER STARTING MOTOR UTILIZING 
WORM DRIVE. 

retion and ignition. It is easier to start and turn an ■ 
engine at 100 revolutions oer minute than at lower or 
higher speeds. 

Power. Seven hundred and forty-six watts equal 
one mechanical horsepower, so by dividing the aver¬ 
age power required in watts by the voltage of the 
system the required amperes may easily be found. 

Drive. The drive is taken from the motor to the 
crankshaft or flywheel through chains or gears. The 

128 


Section 4 

ELECTRIC LIGHTING AND STARTING 129 

reduction may take place through trains of spur gears, 
planetary gearing, eccentric gears, internal gears or 
worm gearing. Combinations of these systems may 
be used and they may be combined with silent chains. 



STARTING MOTOR APPLIED TO CLUTCH SHAFT. 

Engagement between the motor and engine may be 
through sliding gears, jaw clutches or friction clutches. 
In some types universal joints are used to prevent strain 
on the bearings. 



STARTING MOTOR DRIVING INTO TRANSMISSION GEARS. 













ELECTRIC GEAR SHIFT. 


Changing the position of the sliding gears in the se¬ 
lective transmission by electricity has proved desirable 
and a great convenience in many cases. The mechan¬ 
ism and its operation are both very simple, being sub¬ 
stantially as follows. 

The shifter rod of the transmission is not attached to 
the hand lever pull rods but has an iron plunger at each 
end, front and rear. These cores are arranged to be 
drawn into a solenoid when current from the battery 
is allowed to pass through the solenoid windings. 
There are four solenoids, one each for low, intermedi¬ 
ate, high and reverse speeds, these corresponding to 
the four iron cores, two on each shifter rod. 

The flow of current to these solenoids is controlled 
by press buttons located on the steering wheel or 
within easy reach of the driver. There are five of these 
switch buttons, one each for low, intermediate, high 
and reverse speeds and one extra button that returns 
the gears to the neutral position from any of the speed 
positions. 

These selector buttons do not make the circuit com¬ 
plete between the battery and solenoids but they make 
the connection that determines which of the solenoids 
the current will pass to when the master switch is 
closed. This master switch makes the connection com¬ 
plete and causes the solenoid to act on the iron core, 
bringing the gears into the desired position for use. The 
master switch is connected to the clutch release pedal in 
130 


Section 4 

ELECTRIC LIGHTING AND STARTING 131 

such a way that the circuit is not completed until the 
clutch is depressed all the way. 

The action is as follows: The operator depresses the 
selector button controlling the speed he desires to use 
and when he is ready to start or move the car in that 
speed he depresses the clutch pedal clear to the floor. 
This closes the master switch and the gears are imme¬ 
diately snapped into position. Allowing the clutch to 
engage in the usual way causes the car to move. 

The operator may now depress the selector button of 
the next speed he desires to use, either higher or lower, 
but this does not immediately shift the gears. When he 
is ready to make the change it is only necessary to 
press the clutch pedal clear down and the shift is made 
positively. 

Pressing the neutral button brings the gears to the 
neutral position through the action of the solenoid and 
a small stop, preventing the gears traveling into an¬ 
other speed position. 


AMMETER READING. 


(1) With the engine and dynamo running and the 
lamps turned off the ammeter should give a reading of 
a steady charge of not more than one-eighth of the bat¬ 
tery capacity in ampere hours at a car speed of fifteen 
to twenty miles an hour and not less than one-ninth 
of the battery capacity with the engine running at its 
highest safe speed. 

Should the reading be zero trouble may be found in 
a defective ammeter, a dynamo not generating or wires 
disconnected. If the reading should show a discharge 
the ammeter connections or dynamo connections may 
be reversed or there may be a bad ground or short cir¬ 
cuit in the charging or lamp switch lines. If the am¬ 
meter shows too high a charge the regulation is at fault 
and if the charge is too low there may be short circuited 
or grounded wires or the dynamo may not be operat¬ 
ing properly. A jumping ammeter hand indicates loose 
connections or that the battery wires are reversed. 

(2) With the engine and dynamo running and the 
lamps turned on the ammeter should show a small 
charge, a small discharge or zero. 

If the indication is a full charge the regulator is at 
fault or else the ammeter does not register properly. 

If the indication is too great a discharge the dynamo 
may not be generating properly or there may be loose 
or broken wires or short circuits or grounds. 

(3) With the engine and dynamo idle and the lamps 
turned off the ammeter should show zero. If it shows 

132 



Diagrams from top to bottom—Dynamo running; lamps off; charge indi¬ 
cation. Dynamo running; lamps on; slight charge or discharge. Dynamo 
idle; lamps off; zero indication. Dynamo idle; lamps on; discharge accord¬ 
ing to lamps. 









































































Section 4 

134 ELECTRIC LIGHTING AND STARTING 

a charge the ammeter is probably out of order and if 
it shows a discharge there are shorts or grounds in 
some of the lines or the cut-out does not open. 

(4) With the dynamo and engine idle and the lamps 
turned on the ammeter should show a discharge of the 
number of amperes required by the voltage and candle- 
power of the lamps turned on. If it shows zero the am¬ 
meter wires may be shorted on each other or one of 
the battery wires may be shorted or the ammeter 
hand may be sticking. Too high a discharge indicates 
a short or ground and too low a discharge indicates a 
defective ammeter. A reading of charge indicates 
wires reversed to the ammeter. 


SECTION FIVE 


ELECTRIC IGNITION 

Design, Construction, Use, Care and Repair of 
Various Units. 


Subjects in This Section Are Arranged in Alphabetical Order 
For Easy References 





BREAKER. 


When the current flowing through a transformer 
coil is suddenly broken or stopped from flowing a very 
high voltage current is induced in the secondary wind¬ 
ing of the coil. This is done by a breaker, the breaker 
having two contact points tipped with platinum, one 
of these points being stationary and carried by the 



MAGNETO BREAKER (Bosch). 


end of a threaded screw. By turning this screw the 
points may be brought pearer together or farther apart. 
This screw is locked in place with a jam nut or spring. 
The other contact point is mounted on a lever which is 
pivoted. As the armature or shaft turns this lever 

3 


28 








Section 5 

4 


IGNITION 


strikes a cam or projection and this cam forces the 
points to separate against the action of a small spring. 
The current from the coil passes through the points 
of the breaker and just as the points separate the spark 
is produced. 

Breakers are usually arranged so that they may be 
rotated part way around the shaft. Rotating the 
breaker in the same direction that its shaft runs causes 
the spark to come later in the piston stroke or retards 
the spark while rotating the breaker the opposite di¬ 
rection to which the shaft runs causes the spark to 



MAGNETO BREAKER. (Splitdorf.) 

come earlier in the stroke and advances the ignition. 

Breakers are used on magnetos and also as separate 
units in connection with batteries and single unit 
coils. In the latter case the breaker is usually com¬ 
bined with a distributor, the coil and switch being sep¬ 
arate. The magneto breaker receives the current from 
the magneto armature primary winding and if the 
magneto is used in connection with a battery the 
breaker may also receive the battery primary current 
when the switch is in the battery position. 


IGNITION 


Section 5 

5 

A breaker cam or projection should have a drop of 
light machine oil applied with a match or toothpick 
once a month but no other oil should ever be applied in 
the breaker case. The points must always be kept 
clean and dry. 

The contact points of a breaker must be kept filed 
clean and smooth and so that they make a full, even 
contact with each other. 

Sometimes a breaker will cause trouble because the 
movable arm does not operate. This may be caused by 
the arm sticking on its pivot or because the spring 
is broken, bent or weak. The arm may possibly be 
broken. 

The adjustable point in the breaker should be set so 
that the points separate about the thickness of a busi¬ 
ness card or one-fiftieth of an inch when fully open. 


COILS. 


The action of a transformer coil is explained in the 
section on Elementary Electricity under Induction. All 
forms of transformer coils have a property known as 
lag. This causes an extremely short interval between 
the time the circuit is broken in the primary winding 
and the time when the spark is produced from the sec¬ 
ondary winding. This forms one of the reasons for the 
advancing of the spark as the engine runs faster. 

Coils are used in many forms in automobile work. 
The armatures of all magnetos carry one or more coils. 
In magnetos that require a separate coil to produce 
the spark there is only one winding on the armature 
that produces a low voltage current for use in the sepa¬ 
rate transformer coil. Magnetos that deliver a high 
tension spark without the use of a separate coil have 
two windings on the armature, one winding generating 
the primary current that is broken in the breaker and 
outside of this winding there is another winding of fine 
wire, this second winding being the secondary winding 
of a transformer coil, the inner winding that generates 
the current acting as the primary winding and the 
armature core being the core of the transformer coil 
thus formed by the two windings. 

Other forms of coils include master vibrators; single 
unit coils for use with magnetos; distributors and single 
spark systems; vibrator coils having a vibrating breaker 
attached to the coil and multiple unit coils having a 
separate coil for each cylinder to be fired. 

6 


IGNITION 


Section 5 

7 

Master Vibrator. This is a coil having a single wind¬ 
ing which is used to operate a vibrator attached to the 
coil. This coil performs no work of current genera¬ 
tion, being used only to operate the vibrator. The mas¬ 
ter vibrator is used in connection with multiple unit 
coils having a separate coil and vibrator for each cylin¬ 
der. It does away with the use of the separate vi¬ 
brators and substitutes its one well made vibrator which 



MASTER VIBRATOR WIRING. 

C, Old coil; V, Master vibrator coil; M, Low tension magneto; T, Timer. 


does the vibrating and breaks the current for all the 
coils. Its advantage is that there is only one vibrator 
to adjust, giving a uniform spark in each cylinder. 

Master vibrator coils usually have three terminals 
but may have only two. If there are three terminals it 
is intended that two of these lead to two separate sets 
of batteries. With the Ford low tension magneto one 































Section 5 

8 


IGNITION 


of these terminals should be connected to the binding 
post on top of the transmission case (the magneto ter¬ 
minal) and the other connected to a set of batteries. 
The third terminal on the master vibrator should be 
connected to the terminal of the old coil that formerly 
led to either the batteries or magneto (low tension mag¬ 
neto only). If this third terminal on the master vibra¬ 
tor is connected to the battery terminal on the old coil 
then the old switch must remain in the battery position 
at all times. If it is connected to the magneto terminal 
on the old coil or switch the old switch must remain 
in the magneto position at all times. 

The exact method of wiring will vary to some extent 
with the make or type of master vibrator purchased. 
The coil of the master vibrator may have two or three 
terminals and they may be marked “B” or “Bat” for 
connection to the battery, “Bl” or “B2” or “Bat 1” 
and “Bat 2” for connection to two separate sets of bat¬ 
teries on the positive terminals of the batteries or “M” 
or “Mag” for connection to the low tension magneto 
terminal. Any terminal marked “B” or “Bat” may be 
connected to the magneto terminal on the transmission 
case of a Ford car. A terminal marked “G” or “Grd” 
should be connected to the metal of the frame or 
grounded. 

Taking it for granted that you are working with a 
2, 3, 4, or 6-unit coil, one or more batteries or sets of 
dry cells or with the Ford magneto the method would 
be as follows: 

1. Screw the master vibrator to the dash of the car 
near the old coil but do not remove the old coil. 

2. Trace the wire running from a battery or from the 
Ford magneto (not both) to the old coil or the old 


IGNITION 


Section 5 

9 


switch. Remove this wire from the coil or switch and 
attach it to one of the magneto or battery terminals on 
the master vibrator, the terminal marked for battery or 
magneto, according to which is used. 

3. From one of the remaining terminals of the master 
vibrator (not from a terminal marked “M” or “Mag,” 
or “B” or “Bat”) run a wire to the old coil terminal 
from which you removed the wire mentioned in rule 
two. 

4. You should now have one terminal left on the 



SINGLE UNIT VIBRATING COIL. 


master vibrator and this terminal should be connected 
to the Ford magneto terminal if not already connected 
to a battery or set of dry cells. This terminal is con¬ 
nected according to its marking, if there is any. (If 
there were only two terminals on the master vibrator 
there are no more connections to make.) 

If the car originally had another connection besides 
those mentioned from the old coil to a Ford magneto or 
another set of batteries, this connection should be re¬ 
moved. 


IGNITION 


Section 5 
10 


5. If the wire mentioned in rule three was connected 
to the magneto terminal of the old coil, then the switch 
on the old coil must be left in the magneto position. If 
the wire mentioned in rule three was a battery wire 
then the old switch must be left on the battery posi¬ 
tion. The switch on the master vibrator is then used 
for switching the ignition on and of! and to either bat¬ 
tery or magneto. 



FOUR UNIT IGNITION COIL HAVING MASTER VIBRATOR 
MOUNTED IN CENTER OF BOX. 

6. This completes the necessary rewiring, as it is 
not necessary to use all the terminals on the old coil. 

7. Turn the adjusting screw on each of the old coil 
vibrators until the platinum points are held tightly to¬ 
gether or run a short wire that will connect the spring 
carrying one of the platinum points to the metal carry¬ 
ing the other platinum point. The idea is simply to 
let the current pass through the coil without causing 
the vibrator to operate. 



IGNITION 


Section 5 

11 

A master vibrator is adjusted in exactly the same 
way that any vibrator is adjusted on any coil. 

Single Unit. This is generally understood to mean 
a transformer coil for mounting anywhere on the car, 
the coil having no vibrator as a general rule. However, 
some single unit coils have vibrators in the coil case. A 



FOUR UNIT COIL AND TIMER WIRING. 

Showing storage and dry cell batteries with two way switch leading to 
common terminal wire and each of the four coils, circuit being completed 
through separate timer wires. 


single unit coil may or may not carry a switch and it 
may be in a wood or metal box of square or cylindrical 
shape. It may have from two to six terminals on its 
case, depending on its use with magneto, battery or 
both. 










































Section 5 
12 


IGNITION 


Multiple Unit. This means a set of coils, one for 
each cylinder of the engine. Multiple unit coils usually 
have a vibrator on each coil although they may be set 
in a box with a master vibrator when they themselves 
will have no vibrators. 

Multiple unit coil boxes usually carry the switch and 
are mounted on the dash or under the floor. 


CONDENSER. 


Whenever a primary current is broken by a breaker 
or vibrator a heavy spark should occur at the breaker 
or vibrator points. This spark would soon burn and 
destroy the points. To absorb the current causing this 
extra spark a condenser is attached to all forms of 
breakers. 

The condenser consists of a large number of sheets 
of tinfoil. These sheets are laid one on top of the other 
with sheets of waxed paper or mica or other insulation 
between them. Half of the tinfoil sheets (every alter¬ 
nate sheet) stick outside the insulating sheets at one 
end of the condenser and the other half stick outside at 
the other end. The sheets sticking out of one end are 
all pressed together and attached to a wire and all the 
sheets sticking out of the other end are attached to¬ 
gether and are fastened to another wire. The whole 
arrangement is then enclosed in an insulating covering 
of wax or other material and only the two wires stick 
out. 

One of the condenser wires is attached so that it 
has a connection with one of the breaker or vibrator 
contacts and the other wire connects with the other 
contact point. The current from one point cannot pass 
through the condenser and short circuit to the other 
point because one-half the sheets of tin foil are sep¬ 
arated from the other half by the insulating sheets. 
While the points are not short circuited, the excess 
current that would make a spark passes into the tinfoil 

13 


Section 5 

14 


IGNITION 


and is absorbed. When the contact points come to¬ 
gether again this absorbed current escapes and does 
no damage. 

Should the insulating sheets become broken or punc¬ 
tured the contacts are short circuited and no spark will 
occur at the plug, or at best a very weak spark. Should 
one of the condenser wires become disconnected from 
one of the contacts a heavy spark will occur when the 
contacts separate. The remedy is a new condenser. 

The condenser is usually carried in the same case 
with the coil or in the base or above the armature in 
a high tension magneto. 


CONTACT POINT CARE. 


The separating points of all breakers and vibrators 
should be fitted with tips of platinum so that they will 
stand the heat of the small spark that occurs when they 
break. Sometimes the platinum is mixed with another 
metal called iridium to make it harder. No substitute 
for platinum should be used as it does not handle the 
current properly. Single platinum contacts are worth 
at least $1.20 or more and as a general rule points 
selling for less than this are not pure platinum. 

In time platinum points wear and burn away and 
when this happens the part carrying the tip may be re¬ 
placed with a new one or the old point may be pried 
or driven out of the hole into which it is riveted and 
a new point bought. The new point has a small part 
that passes through the hole and is then riveted over 
on the side opposite the contact. In most cases it is 
best to secure the entire screw, arm or spring carrying 
the contact point. 

The surfaces of platinum points that touch each 
other must be kept clean and bright and free from pits, 
roughness or burned spots. Points should be examined 
occasionally and if not in good shape they should be 
dressed by filing with a very fine flat file. When they 
are filed the surfaces must meet each other exactly even 
at all points, not only touch at one side or in the center. 
Points may be easily dressed by drawing a specially 
prepared strip of cloth between them while they are 
pressed lightly together. This cloth is covered with 

15 


IGNITION 


Section 5 
16 

emery or carborundum on both sides and being of an 
even thickness makes the contacts meet each other 
properly when the work is finished. 


DRY CELLS. 


These cells are used for furnishing primary current 
for use in the transformer coil while starting the en¬ 
gine and before the engine has sufficient speed to pro¬ 
duce a spark from the magneto. To a certain extent 
dry cells provide a reserve ignition system that may 
be used in case the magneto fails. 

Dry cells are composed of a zinc shell enclosed in a 



TYPICAL DRY CELL. 


cardboard holder with a cardboard bottom. Inside 
the zinc shell are the active materials that act on the 
zinc and in the center is a stick of carbon. Inasmuch 
as the zinc forms one of the elements of the cell it must 
not be allowed to touch any metal or conductor. To 
insulate the zinc it has the cardboard cover over it and 
this cardboard cover must be preserved without break- 

17 




Section 5 

18 


IGNITION 


ing or chafing through because it is as much a part of 
the cell as anything else. 

Attached to the zinc shell is a small brass screw and 
nut, this being the negative terminal of the cell. To 
the carbon in the center of the cell is fastened another 
small screw and nut forming the positive terminal. 
The center terminal in any dry cell is the positive and 
the outside terminal is the negative. In using sets of 
dry cells in a battery care must be used to see that the 
negative terminal does not touch' another negative 



AMMETER FOR TESTING DRY CELLS. 

terminal or the zinc of another battery or any piece 
of metal such as the walls of the battery box. 

A single dry cell produces a voltage of 1%, this 
voltage changing but little whether the cell be new 
or old. A dry cell contains about ten ampere hours, 
although much of this amount may be lost through 
improper use, handling or from old age. When the 
terminals of a dry cell are short circuited the flow 
should be between twenty and thirty amperes if the 
cell is new and good. In testing a dry cell use an am¬ 
meter and touch the points only for a moment. A high 


IGNITION 


Section 5 

19 


discharge from a dry cell causes it to lose its ability 
to do useful work and if the ammeter or any other 
conductor is held in connection with the terminals for 
more than a second at a time the battery will lose 
much of its life. When a battery is used in connection 
with a coil the discharge is low enough so that the cell 
is not damaged. When testing a number of cells try 
each cell separately from the rest. When a cell shows 
less than six amperes it should be thrown out of the 
battery and replaced with a new one. It is not best, 
however, to place old and new cells in the same cir¬ 
cuit because the old cells prevent the proper flow from 
the new and cause the new cells to overcome the high 
resistance of the old ones. The new cells will quickly 
be brought down to the level of the old ones. Neither 
should different sizes or makes of cells be used to¬ 
gether. A battery showing a high amperage on test 
is not necessarily a good and long-lived battery be¬ 
cause the maker can use a strong electrolyte and cause 
a poorly built battery to show a good test. 

A dry cell should not be called upon to give a flow 
of more than one-half ampere if its full life and current 
is to be obtained. Under this amount of flow the aver¬ 
age life of dry cells in ordinary use will be about 
twenty hours of actual use. Dry cells lose their power 
with age whether used or not. 

Should it be necessary to restore an old dry cell 
it may be done temporarily by punching a hole in the 
top, bottom or side of the cell and pouring water or 
water mixed with vinegar or acid into the hole. This 
will cause the cell to deliver current for a short time. 
There is no method of restoring an old dry cell that 

will prove at all satisfactory for continued use. 

29 


Section 5 

20 


IGNITION 


Dry cells are connected together into batteries, thus 
increasing either the voltage or amperage or both, ac¬ 
cording to the type of connection used. Cells are 
connected with short pieces of insulated wire bared 
at the ends and twisted or turned around the cell termi¬ 
nal or they may be connected with specially made bat¬ 
tery connectors. These connectors have brass or cop¬ 
per terminals with holes that go over the battery screws 



DRY CELL CONNECTIONS, 
i, Series; 2, Multiple; 3, Multiple-Series. 


and the wire is soldered into the terminal, making a 
good electrical joint. These connectors cost only about 
a cent each so should always be used. If the coiled 
wire is used care should be exercised that no loose 
strands of wire stick out and touch any metal parts. 
Another type of connector has spring ends which have 
two holes, one in each end of the spring. Pressing the 
spring together brings the holes in line and they are 













IGNITION 


Section 5 

21 

then passed over the screws of the cells and the spring 
tension holds them in place. These cost several times 
what the plain connectors do but are easier to use. In 
using plain connectors the cell terminal nuts must be 
screwed tight with the pliers. Screwing them down 
with the fingers allows them to come loose and give 
trouble. 

If it is desired to obtain more voltage than one cell 
will give several cells may be connected in series. This 
means that the positive of each cell is connected to the 
negative of the next” cell, the positive of that cell being 
connected to the negative of the next one and so on. 
This leaves one positive and one negative terminal at 
each end of the set. This connection increases the volt- 



“BULL DOG” BATTERY CONNECTOR. 

age according to the number of cells, the voltage 
being found by multiplying the number of cells by 
iy 2 (the voltage of one cell). To secure six volts it 
would be necessary to use four cells because 4 times 
iy 2 is six. In actual practice, however, it is best to 
use one additional cell to overcome the resistance of 
the whole battery and to make sure of the full voltage. 
Thus, to obtain six volts in actual use we would use 
five cells in place of four. 

The amperage may be increased by connecting the 
cells in multiple. This connection requires that the 
negative of each cell be connected to the negative of 
the next cell and so on, all the negatives being con- 


Section 5 
22 


IGNITION 


nected together and all the positive terminals being 
connected together. This makes one negative wire 
and one positive wire. This connection causes the 
amperage of the battery to equal the amperage of one 
cell multiplied by the number of cells used. Thus, 
four cells, each giving a flow of twenty amperes, will 
give a flow of eighty amperes if connected in multiple. 

When it is desired to increase both the amperage 
and voltage and also to increase the useful life of the 
cells a connection known as multiple-series is used. 
To make this connection: Take the number of cells 
required to give the desired voltage and connect them 
in series as directed. You can then use two or more 
of these series sets of cells. Each set forms a battery 
giving the required voltage. These sets or batteries 
are then connected in multiple, fastening the end neg¬ 
ative terminals of all the sets together and fastening 
the end positive terminals of all the sets together. 
This gives the voltage of one set and the amperage 
may be found by multiplying the amperage of one 
cell (not one battery) by the number of sets used. 

If a series set of cells will last a certain number of 
hours a multiple series connection of two sets in series 
will last four times as long. This cuts the cost in two 
because, while the multiple series battery costs twice 
as much, the life is four times as long. 


DISTRIBUTOR. 


A distributor is a device that takes the high tension 
or secondary spark plug current from the single unit 
transformer coil and by making several contacts, one 



COMBINED TIMER AND DISTRIBUTOR. 

Showing rotating timer contact roller in lower part and the distributor 
contact above. On the bottom is shown the single timer terminal and on top 
are the high tension terminals, the center one coming from the coil and the 
outer ones leading to the spark plugs. 


after the other in rotation, sends the spark current to 
the right cylinder at the time the piston is in the tiring 
position. The time at which the spark occurs in the 

23 





Section 5 

24 


IGNITION 


stroke is governed by the instant at which the breaker 
points stop the flow of current in the coil, or when the 
timer causes current to flow, the distributor only serv¬ 
ing to send this current to the right cylinder of the 
engine. 

Distributors are used on all magnetos for engines 
of more than two cylinders; in connection with break¬ 
ers and single spark systems using a battery current 
without a magneto and also as a separate unit com¬ 
bined with an ordinary timer in connection with one 
vibrating coil. 

The magneto distributor is described under mag¬ 
netos. 

The wires are attached to the terminals of either 
type just as directed for the magneto distributor, the 
piston of one cylinder being brought to the firing posi¬ 
tion and a wire run from the terminal of the distributor 
that is making contact through the rotating brush or 
contact inside the distributor to the spark plug of that 
cylinder. Inasmuch as the distributor is always used 
with some form of breaker, timing and setting the 
breaker brings the distributor into the proper position 
at the same time. 

The center or middle terminal on any form of dis¬ 
tributor should be connected to the transformer coil 
that furnishes the spark current. When a distributor 
and breaker or timer are made together the distributor 
part is always farthest from the driving shaft or on 
top of the timer. The timer or breaker contacts are 
on the bottom or side or part nearest the driving 
shaft, the distributor terminals being on top or farthest 
from the shaft. 

The timer or breaker contacts are usually marked 


IGNITION 


Section 5 

25 

for proper connection. A timer for use with a dis¬ 
tributor has only one terminal besides the grounding 
terminal. In many cases there is no grounding 
terminal so that the single connection is made from 
the timer to the low tension terminal on the coil or the 
switch. In any case this single terminal must be con¬ 
nected in such a way that the primary current from 



the battery flows to it, either before or after this cur¬ 
rent passes through the coil or switch. 

Connections for breakers or single sparkers usually 
have only two terminals, one for the ground connec¬ 
tion and the other for the breaker contact point that 
is carried on the adjusting screw. To find the breaker 
contact touch one end of the tester to the metal 








































Section 5 

26 


IGNITION 


of the breaker and the other end of the tester to the 
terminal to be tested. When you turn the shaft, if the 
lamp lights and goes out this terminal is the breaker 
terminal and should be connected to the coil terminal 
marked “Breaker” or “Int.” Most breakers or spark- 
ers have their terminals plainly marked with letters or 
abbreviations. 

The contact brushes and points inside the dis¬ 
tributor should be kept clean and smooth and no oil 
should ever be used at any point inside the distributor, 
although oil may be used in the timer or breaker. 


IGNITION SYSTEMS. 


Ignition systems are divided into several types ac¬ 
cording to the parts used and their arrangement. 

Single ignition means a system using a high ten¬ 
sion magneto without any batteries or separate coils, 
the magneto making the spark current without outside 
help or attachments. 

Set spark ignition means a system having no means 
for advancing or retarding the time of the spark, the 
breaker being placed in the best position for average 
running and left there always. 

Double ignition means a system including a high 
tension magneto with or without a coil, this magneto 
having a set of spark plugs and wires used for the 
magneto only. In addition to the magneto there is 
some form of battery ignition system, this battery 
ignition system having another and entirely separate 
set of spark plugs and wires. Either system of a 
double set could be entirely removed without affecting 
the other system and the engine would still run. 

Battery ignition means any ignition using the bat¬ 
tery current for running of the engine. 

Dual ignition means a system of ignition using a 
magneto, with or without a coil and in addition a bat¬ 
tery and coil. Some parts, usually the breaker, plugs, 
high tension wires, distributor and switch, being 
used for both systems so that the complete removal 
of one entire system would put the other one out of 
operation. Some forms of dual ignition have sep¬ 
arate breakers for the magneto and battery current. 

27 


Section 5 

28 


IGNITION 


Duplex ignition is a form of dual ignition. 

Variable spark ignition is any system having means 
for advancing and retarding the spark to change the 
time at which it occurs in the stroke. 

Transformer coil ignition is an incorrect name for 
dual ignition inasmuch as all forms of high tension 
jump spark ignition use a transformer coil in some 
form. 

Low tension ignition does not use a transformer 
coil but causes the spark by separating two contacts 
inside the cylinder, these contacts carrying a current 
of low voltage and high amperage. 

Make and break ignition is low tension ignition. 


LOW TENSION IGNITION. 

A low tension or make and break ignition system 
consists of a magneto generating a large volume or 
amperage of current at from 20 to 30 volts pressure 
and means for leading this current into the combus¬ 
tion chamber of the cylinder where it passes from a 
stationary contact point to a movable point. 



MAKE AND BREAK IGNITION COIL. 


This movable point is made to separate from the 
stationary point producing a bright, hot spark at the 
moment of breaking. 

There is also means for holding these contacts to¬ 
gether with a spring and for causing them to separate 
at the instant the spark is wanted. This system 

29 




Section 5 

30 


IGNITION 


has means for changing the time of breaking and of 
the spark during the stroke. 

Some forms use a spark coil to make the current 
give a larger and hotter spark. This spark coil is not 
a transformer coil, having only one winding with a 
terminal at each end of this winding. Causing the 
current to flow through this coil increases the spark 
heat and size. 

The stationary contact is insulated from the metal 
of the cylinder by means of a mica or stone bushing 
and both stationary and moving contacts are carried 
on a plate that is bolted over a hole in the cylinder, 
usually over the inlet valve. 

The contacts are held together by a light spring 
and are made to separate quickly when a push rod 
slips past the sharp end of a small lever arm attached 
to the moving contact but on the outside of the cyl¬ 
inder. 

The advance and retard of the spark is effected by 
a worm and pin arrangement that shifts the position 
of the push rod or the contact lever arm. 

The operating shaft or push rod receives its power 
from the valve cam shaft or from another shaft driven 
from the crank shaft. 

Each time the contacts separate there is a spark 
produced and before another spark can be had the 
contacts must be brought together long enough for 
the current to again flow through the circuit. 

In order to produce a good spark the break must 
be made very quickly, more quickly than the ordi¬ 
nary movement of the parts. This is accomplished 
by having a moving arm operated from an eccentric 
on top of a shaft, this arm pushing against a lever 


IGNITION 


Section 5 

31 

which is held against the arm by a spring. The lever 
and arm are made short enough so that when the arm 
reaches nearly to the end of its movement the end of 
the lever trips or slips back and this quick movement 
causes the break to come suddenly. 

The contact points at which the spark occurs must 
be kept clean and bright at all times by filing or sand¬ 
papering them. 

The tension of the small spring must be great 
enough to cause a good firm contact between the 
points and this contact must be held closed for as 
long a time as is possible to give the proper current 
flow. 

The insulation must be perfect on all wires, short 
circuits or grounds will cause the loss of all the cur¬ 
rent generated. 

The moving parts outside the cylinder should be 
oiled daily with a light machine oil and should be 
kept clean and free from dirt and dust. 

In using a low tension ignition, system it is not 
usually possible to advance the spark timing as fast 
or as far as with the jump spark system. Before start¬ 
ing the engine the spark must be fully retarded or 
injury is almost sure to result in cranking. 

Although a low tension magneto has no breaker 
or distributor it must be correctly set so that the 
break at the contacts comes just as the magneto arma¬ 
ture winding is delivering its greatest flow. The break 
should come when there is a space of about one-fourth 
inch between the edge of the pole piece attached to 
the magnet and the metal core of the armature. This 
space should show or appear on the side of the mag¬ 
neto so that when the magneto is turned still farther 


IGNITION 


Section 5 

32 

in the direction in which it runs the space gets larger, 
not smaller. This position is the point at which it is 
hardest to turn the armature shaft by hand. Trying 
the magneto by turning by hand will usually give 
good enough timing if the gears are meshed so that 
the contacts separate in the cylinder when the arma¬ 
ture shaft turns hardest. 

On account of the large amperage compared to the 
jump spark system the wires used should have more 
copper conductor. They should never be less than a 
number 12 and should be well insulated. 

Common troubles that may be looked for in make 
and break ignition systems are as follows: 

The contact points may be dirty, pitted, sooted or 
worn away. 

The points may not touch for long enough. 

The wires may be short circuited or grounded. 

Moving parts may stick so that there is no make or 
break. 

Insulation on the stationary contact may be broken, 
leaking or covered with soot or oil in the cylinder 
end. 

The parts may have slipped so that the spark comes 
at the wrong time. 

The magneto may need remagnetizing of the mag¬ 
nets. 

The bushing through which the movable contact 
is operated may be so worn as to affect the timing or 
admit air. 

The timing or advance and retard is changed by al¬ 
tering the amount of movement or throw of one of 
the levers. This may be changed in some systems by 
loosening a lock nut at the top of the shaft that turns 


IGNITION • 


Section 5 

33 


from the cam or gear shaft and then turning the ro¬ 
tating part or eccentric or lever until the points are 
seen or heard or felt to jump apart. This breaking 
should come when the flywheel has been turned one 
inch past the point where the piston is at top center 
at the end of the compression stroke, with the spark 
lever in the fully retarded position. The engine should 
be turned one full turn after the exhaust valve closes 
and brought so that the piston is at the top of its 
stroke. Then turn the flywheel about one inch far¬ 
ther in the direction in which it runs. With the locking 
nuts loose, turn the eccentric or part that moves the 
trigger or tripping arm in the same way that it turns 
until the points just separate. Lock the parts in this 
position. 

A low tension system may be changed to a high 
tension system by boring and threading the hole that 
held the stationary contact point so that it will take 
an ordinary spark plug. It is usually easiest to bore 
the hole and tap it one-half inch standard pipe thread. 
Replace the magneto with a high tension or dual 
type of magneto or else place a timer or breaker or 
single sparker on the old magneto shaft and use a 
vibrating coil or the coil made for the outfit used. 
This system can then be wired up and used, neglect¬ 
ing or removing the other make and break parts. 


MAGNETOS. 


Magnetos generate current in the same way that 
dynamos act but the magneto has only one coil around 
its armature, uses no commutator and is built with 
permanent magnets. Some magnetos really have two 
parts of this coil wound together on the armature 
but the outside part is a secondary winding of a trans¬ 
former coil and does not generate current in the same 
sense that the primary winding does. 



HIGH TENSION MAGNETO ARMATURE. 

From right to left showing the breaker, the ball bearing, the case covering 
the condenser, the coil of wire on the iron core, the gear that drives the 
distributor, the high tension collector ring and the tapered driving shaft. 

The magneto consists of the armature with its low 
tension winding and a separate transformer coil 
mounted at some other place on the car, or it may 
have both primary and secondary windings on the 
armature. In addition to these parts there is a breaker 
mounted at one end of the armature shaft and a 
distributor driven through gears from the armature 
shaft. Terminals are fastened to the breaker, dis- 

34 


IGNITION 


Section 5 

35 


tributor and base and also to brushes that collect the 
high or low tension current from the armature in some 
machines. These terminals are usually marked so that 
wires may be run to the corresponding terminals of 
the coil and switch. 

The breaker and distributor always have removable 
covers for convenience in timing or setting the posi¬ 
tion of these parts. 

Magnetos are driven from any moving shaft and 
usually have a form of universal joint called an Old¬ 
ham coupling between the armature shaft and the 
driving shaft. This Oldham coupling is in three 
pieces, two pieces that fasten respectively to the end 
of the driving ^haft and to the end of the armature 
shaft. These pieces have slots cut across their face 
and the piece that goes between them has projections 
on each side that fit into these slots. This allows a 
slight motion and prevents strain on the armature 
shaft bearings. 

A single cylinder magneto should turn at half crank 
shaft speed, or, if it turns at crank shaft speed, every 
second spark will come at the end of an exhaust stroke 
and do no harm. 

A two cylinder magneto on an opposed horizontal 
engine gives a spark in each cylinder at the same time, 
but, while the spark goes to one cylinder at the end 
of its compression stroke and fires the charge, the 
other piston is at the end of its exhaust stroke so 
that the spark in it does no harm. 

A three cylinder magneto should operate at 1% 
times crank shaft speed or else it may have two cams 
in the breaker and operate at only % crank shaft 
speed. 

30 


IGNITION 


Section 5 

36 



MAGNETO PARTS. 

i. Distributor cover; 5, Distributor gear; 7, End plate for breaker and 
distributor; 8, Armature bearing holder; 18, Pole pieces; 10, Base date- 
46, Armature cover; 55, Breaker case; 56, Rear end plate; 58D, Compound 
magnet; 58E, Single magnet; 127, Armature tunnell; 156, Distributor brush 


























IGNITION 


Section 5 

37 



MAGNETO PARTS. 

True high tension, waterproof. (Splitdorf.) 64, Armature gear; 73, 
'Driving gear key; 74, Driving gear nut; 165A, Distributor gear; 1458, Ad¬ 
vance and retard stop; 1840, Breaker cover holding spring; 1854A, Breaker 
cover holding spring; 2486, High tension collector cover; 2509, Breaker con¬ 
tact; 2537A, Breaker plate; 2583, High tension collector ring; 2587, Magneto 
base; 2710, Spark plug wire terminal; 2793, Armature housing; 2797, Con¬ 
denser; 2800, Condenser clamp; 2804, End plate cover; 2805, End plate 
cover; 2806, Conductor bar insulation; 2808, Distributor cover; 28x6, Mag¬ 
nets; 2825, Dust and water proof cover; 2826, Distributor center contact; 
2829, Distributor cover screw; 2844, Breaker holding screw; 2876, High 
tension conductor bar; 2925, Breaker armature contact; 2926, Breaker cover; 
3008, Distributor shaft oil well; 3039, Distributor insulation; 3048, Dis¬ 
tributor shaft. 





















































































































Section 5 

38 


IGNITION 


A four cylinder magneto has two cams in the break¬ 
er and operates at crank shaft speed. 

A six cylinder magneto has two cams in the break¬ 
er and operates -at 1% times crank shaft speed. 

Three, four and six cylinder engine magnetos re¬ 
quire a distributor. 

For two cycle engines the speed of the magneto 
must be doubled. 

If the magnets must be removed from a permanent 
magnet magneto first loosen the screws holding them 
to the pole pieces or base. Then lay a piece of iron or 
steel from one leg to the other of the magnet and as 
far down toward the poles as possible. Lift the mag¬ 
nets carefully off while pushing this piece of iron or 
steel down until it rests from pole to pole. Leave 
this piece on the magnets all the time they are off 
the magneto. 

If you take two permanent magnets and touch one 
pole of one to one pole of the other these poles may 
pull or attract each other. Turn one of the magnets 
around until you find two poles, one on each magnet, 
that do not attract each other. These poles, that do 
not attract each other, must be placed together on 
the same side of the magneto. If two magnets are 
placed on a magneto in such a way that they tend to 
stick together the magneto will not'make any cur¬ 
rent. 

As explained under dynamo action the current is 
generated or induced by causing a change in the lines 
of force acting through a coil of wire. In the ordi¬ 
nary magneto and dynamo this change is made by 
turning the armature. There is another type called 
an inductor magneto or generator in which the coil 


IGNITION 


Section 5 

39 



MAGNETO PARTS. 

Separate coil type of instrument. 8, Magneto base; 55, Breaker cam 
nut; 64, Armature gear; 71, Breaker cam nut; 73, Driving gear key; 115, Pis- 
-tributor housing; 122, Breaker terminal; 142, Advance and retard stop; 165, 
Distributor gear; 172, Distributor shaft bearing; 176, Distributor gear; 178, 
Distributor moving contact; 213, Distributor shaft cover; 224, Safety spark 
gap; 226, Front plate screws; 276, Armature gear cover; 287, Breaker arm 
roller; 297, Armature grounding brush; 337, Distributor insulation; 363A, 
Armature shaft bearing; 364, Distributor shaft bearing; 390, Center distribu¬ 
tor brush; 415, Magnets; 438, Terminal for outside coil; 736, Armature 
bearing oil hole; 790, Breaker adjusting screw; 791, Breaker plate; 792, 
Breaker arm (movable); 798, Breaker screw holder; 805, Breaker arm hold¬ 
ing spring; 807, Grounding terminal; 821, Terminal for outside coil; 826, 
Distributor wire terminal; 828, Distributor cover; 1061, Breaker cover; 
1671, Armature wire; 1693, Breaker cover holding spring; 1698, Breaker 
cover holding spring; 1709, Collector ring insulation; 1712, Collector ring; 
1726, Collector brush; 1764, Distributor cover screw; 2151, Armature cover; 
2406, Collector terminal insulation; 2407, Collector for armature current; 
2622, Condenser cover; 297A, Breaker cover brush. 



























































































































Section 5 

40 


IGNITION 


and magnets remain stationary and the change of 
magnetic field is caused by moving the pole pieces 
or inductors. 

This type has U shaped permanent magnets like any 
other magneto. Carried on a shaft in the same position 
as the ordinary armature would be carried are two 
pieces of iron. One piece sticks out from the shaft at 
one side, near one end, and the other piece sticks out 
from the shaft at the other end, but directly opposite 
to the direction the first piece extends so that one piece 



MAGNETO INDUCTORS. 

Showing stationary coil mounted around shaft between iron inductors. 


sticks out from one side of the shaft and the other from 
the other side. These pieces extend out from the shaft 
to a point very close to the magnet poles. 

With the shaft in one position the inductor piece at 
one end of the shaft is near the positive pole of the 
permanent magnets and the inductor piece at the other 
end of the shaft is near the negative pole of the mag¬ 
nets. In this position the lines of force will flow from 








IGNITION 


Section 5 

41 


the positive pole into one inductor, through the shaft 
to the other inductor and into the negative pole. This 
makes the lines of force flow through the shaft toward 
one end because the inductors are about two inches 
apart on the shaft. 

As the shaft is turned the inductor that was near the 
positive pole comes near the negative and the one 
that was near the negative comes nearer the positive. 
The lines of force still flow from the positive to the 
negative pole, but, as the inductors have changed 
places, the lines of force flow through the shaft in the 
other direction. 

On the shaft between the two inductors there is a 
stationary c;oil of wire through which the shaft passes. 
It will be seen that the lines of force flow first in one 
direction through the center of this coil (the center 
being the shaft) and then reverse and flow in the 
other direction as the shaft is turned. This causes an 
induced current to flow in the coil. 

The Ford magneto is of a peculiar type of low ten¬ 
sion instrument generating from six to twenty-five 
volts, depending on its speed. The Ford magneto is 
part of the flywheel and is contained in the case with 
the transmission at the back of the cylinders and crank 
case. On the top of the transmission case is a termi¬ 
nal through which the current from the magneto 
comes, the other end of the winding being grounded 
inside the case. The current from this terminal is 
used with a timer and four unit set of vibrating coils 
in the same way that a battery current would be used. 

The Ford magneto is composed of a number of V 
shaped permanent magnets fastened around the face 
of the flywheel with their poles pointing toward the 


Section 5 

42 


IGNITION 


outer edge of the wheel. The negative poles of two 
adjoining magnets are next to each other and the posi¬ 
tive poles of each two adjoining magnets are together. 
This set of magnets revolves with the flywheel, being 
driven by the engine. Facing these magnets is an 
equal number of coils mounted on a stationary part of 
the transmission case. The ends of the cores of this 
ring of coils come within l/32nd inch of the poles of 
the magnets on the flywheel. All the coils are joined 
together by conductors and when the magnets revolve 
there is an alternating current produced in the coils 
which can be used for ignition or lighting but not for 
storage battery charging. 

A permanent magnet magneto will lose some of its 
power if mounted on a base or plate of iron or steel. 
Iron or steel will carry the magnetism from one pole 
to the other without the magnetism passing through 
the armature or coils. Any other material except iron 
or steel may be used for magneto bases. 

There may sometimes be sufficient play or lost 
motion in the shafts, gears or couplings that drive the 
magneto to make a serious difference in the timing of 
the spark. Play in these parts or in the chains driving 
the magneto shaft may cause overheating, loss of 
power, missing and irregular running of the engine. 
The play should be removed and with it will often 
go many troubles hard to locate. 

All standard forms of separate magnetos should 
have about two or three drops of light machine oil 
dropped into the holes on the magneto about once a 
month. There are usually two holes or sets of holes 
either covered or open, one set being at one end of the 
magneto and the other set at the other end. There 


IGNITION 


Section 5 

43 


may only be one set at one place, tubes leading from 
here to the parts to be oiled. Never oil the distributor 
and do not give more oil than directed above unless 
there are directions on or with the magneto that give 
other instructions. 

Magneto Troubles. 

1. Breaker points pitted or worn. Dress with a fine 
file. 

2. Breaker points separated too far. Adjust so they 
will open the thickness of a thin card. 

3. Breaker points not separating. Adjust as above. 

4. Loose parts in breaker. Adjust and tighten. 

5. Breaker arm sticking. Take off and adjust by 
smoothing with sandpaper. 

6. Brushes dirty. Smooth with sandpaper. 

7. Brushes broken. Replace with new ones. 

8. Brushes sticking or binding. Clean with sand¬ 
paper or gasoline. 

9. Broken brush springs. Replace with new ones. 

10. Magnets on wrong. Magnets must be on the 
magneto with both negative poles on one side and both 
positive poles on the opposite side. The poles that try 
to keep away from each other must be put together. 

11. Magnets weak. Must be remagnetized. 

Magneto Timing (Armature Position). The arma¬ 
ture of the magneto should be set, relative to the break¬ 
er, so that the greatest flow of current comes just as 
the breaker points cause the flow of current to stop 
passing through the armature coil. In most mag¬ 
netos, this is the time at which the points separate, 
although magnetos have been built in which the cur¬ 
rent stops flowing through the armature coils when 
the points come together. This is accomplished by 


Section 5 

44 


IGNITION 


connecting the points in such a way that when they 
are open the current has to flow through the coil but 
when the points come together they provide a path 
of less resistance than the coil so that there is no 
further flow through the coil. However, the great 
majority of magnetos have the ends of the winding 
on the coil connected to the breaker points so that 
when the breaker separates the current stops flowing 
in the coil and produces a spark in the secondary 
winding. 



ARMATURE POSITION. 

D, Gap between edge of pole piece and edge of armature core. 

The armature and breaker require different setting 
relative to the distributor according to whether the 
armature rotates clockwise or anticlockwise. The di¬ 
rection of armature rotation is always taken from the 
drive end of the armature shaft. To decide which 
way the armature turns look at the shaft from the 
drive end and if it goes right handed or the same way 
the hands of the clock move it is a clockwise magneto, 







IGNITION 


Section 5 

45 

if it goes lefthanded or the opposite way from the di¬ 
rection the hands of the clock move it is an. anti¬ 
clockwise magneto. N 

The breaker itself may usually be changed for either 
direction of rotation by changing the cam or the 
movable arm. Removing either of these parts and 
turning them over before replacing will allow the 
magneto to rotate the opposite way. In many mag¬ 
netos there are small arrows on these parts indicating 
which way the shaft should turn. Some magnetos are 
built in such a way that the direction of rotation can¬ 
not be changed outside the factory. 

It may also be possible to remove the pins or screws 
that limit the breaker box movement and place them in 
a new position at which the points open at the correct 
time. 

The distributor is properly set by changing the mesh 
of the gears between the distributor and the armature 
shaft. 

To find the proper point at which the breaker points 
should cause the current to stop flowing in the arma¬ 
ture coil, usually the time of breaking, remove the 
cover that is over the top of the armature between the 
magnets. The two pieces of metal that are fastened 
to the ends of the magnets are called pole pieces and 
fill up most of the space between the magnets and 
armature. 

You will notice that the armature is made from a 
piece of iron around which is wound a coil of wire.- 
This iron is between the pole pieces whenever the coil 
can be seen. As the armature is turned the coil dis¬ 
appears and more of the iron of the armature comes 
into view. Keep turning the armature in the direc- 


IGNITION 


Section 5 

46 

tion it should run until the part of the iron that you 
can see extends from pole piece to pole piece and so 
that none of the coil can be seen. 

If you are turning the armature clockwise the iron 
will then leave the left hand pole piece first; if you 
are turning it anticlockwise the iron will leave the 
right hand pole piece first. 

When the iron of the armature has left the edge of 
the pole piece enough to show about one-eighth of an 
inch gap between the edge of the pole piece and the 
edge of the iron of the armature, the breaker should 
open or stop the current flow. 

While making this test the breaker or spark timing 
lever should be as far advanced as possible, that is 
the movable part of the breaker or cover should be 
turned as far as possible in the opposite direction to 
which the shaft turns. 

With the breaker points just opening or stopping 
the flow of current the gears between the distributor 
and armature shaft should be. placed in mesh so that 
the moving brush or contact on the distributor is just 
starting to make contact with any one of the segments 
or collecting brushes that carry the current to a spark 
plug wire. This moving brush or contact should then 
move farther over the stationary brush or contact as 
the armature is turned in the direction it should run. 
This test should be made with the spark fully advanced. 

Magneto Timing (Breaker). 1st. Turn the crank 
shaft by means of the hand crank or flywheel until the 
exhaust valve on number one cylinder (next the ra¬ 
diator) just closes. 

2d. Turn the crank or flywheel just one even turn 
from this point which will bring the piston just a little 
ways down on the firing stroke. 


IGNITION 


Section 5 

47 


3d. Set the breaker case and spark lever in the fully 
retarded position by turning the breaker case just as 
far as it will go in the same direction that the arma¬ 
ture shaft revolves and be sure that it remains in this 
position while timing. 

4th. Turn the magneto armature shaft in the same 
direction that it runs until the breaker points just sep¬ 
arate and then mesh the gear on the end of the arma¬ 
ture shaft with the gear that drives it from the crank 



MAGNETO BREAKER. 

At the bottom is seen the fibre point that strikes against the cams in the 
case, causing the points to separate. 

shaft while the armature, breaker and piston are in 
the positions given. If the gears (or sprockets in a 
chain driven magneto) will not mesh in exactly this 
position turn the armature backwards just enough for 
the gears or sprockets to mesh. 

Magneto Timing (Distributor Wiring). 1st. After 
timing the breaker and without moving anything 
about the engine or magneto that has been timed, re¬ 
move the distributor cover and notice which segment 


IGNITION 


Section 5 

48 

or brush the moving contact is touching. Run a wire 
from the terminal on the outside of the distributor 
that is connected with this contact to the spark plug 



MAGNETO WITH BREAKER COVER REMOVED. 

of number one cylinder. If there is any doubt as to 
which contact on the outside of the distributor con¬ 
nects with the movable brush at this time test them 










MAGNETO WITH DISTRIBUTOR COVER REMOVED. 

Showing the revolving contact brushes carried on the distributor gear. 
At the right is the cover carrying the segments with which the brushes 
make contact. 

to bring the piston so it is starting down on the power 
stroke as described above. 

2d. Turn the engine until the exhaust valve on num¬ 
ber two cylinder just closes, then give it one more 
full turn from this point. 


IGNITION 


Section 5 

49 


with the tester by touching the ends of the test wires 
to the inside and outside contacts of the distributor 
until you find which ones are connected together. 

If, for any reason, it is desired to attach the wires 
from the distributor to the spark plugs when the mag¬ 
neto is already mounted and timed it is only necessary 









Section 5 

50 IGNITION 

3d. Examine the distributor once more, without 
disturbing the spark plug wire already placed, and 
connect the terminal of the segment or brush now 
making contact with the moving contact, with the spark 
plug of number two cylinder. 

4th. Do the same with the remaining cylinders as 
was done with cylinders number one and two. 

If you find the firing order of the engine and then 
watch to see which way the movable part of the dis¬ 
tributor revolves, it is only necessary to attach num¬ 
ber one spark plug wire and then place the wire for 
the next cylinder to fire on the distributor terminal 
next to make contact as the magneto turns in its right 
direction. All of the spark plug wires may be placed 
after number one by connecting the wires from the 
cylinders in regular firing order to the distributor 
terminals in the order in which they make contact. 

The Bosch magneto, Model NU4 has its distributor 
and high tension terminals on the drive end of the 
armature shaft. Two terminals are on each side of the 
shaft, the sets being directly opposite each other. 

After timing the magneto according to the breaker 
as with any other type, attach the spark plug wires 
from cylinders 1 and 3 to the two terminals on one side, 
placing No. 1 next the magnets. Place the spark 
plug wires from cylinders 2 and 4 on the opposite side 
of the armature shaft with No. 2 wire next the 
magnets. 

Crank the engine, and if it will not run, place No. 1 
wire where you now have No. 3, and No. 3 where you 
have No. 1. Interchange wires No. 2 and 4 in 
the same way and the engine will fire correctly. 


IGNITION 


Section 5 

59 

tion and mark these terminals (we will say they are 
marked red). Now turn the switch to the magneto 
position and find two terminals that complete the cir¬ 
cuit but break it when the switch is turned from the 
magneto position. Mark these two terminals also (we 
will say they are marked blue). Now connect the 
coil terminal that has both a red and blue mark to 
the breaker terminal on the magneto, connect the 
terminal marked red only to the remaining battery 
terminal and the one marked blue only to the armature 
or magneto terminal on the magneto. If there were 



WIRING OF MAGNETO WITH DASH COIL. (Splitdorf.) 


five terminals after connecting the high tension to the 
distributor find two terminals that make a circuit all 
the time no matter what position the switch is in. Con¬ 
nect one of these terminals to one side of the battery 
and the other one to the ground terminal on the mag¬ 
neto. This leaves three terminals which are connected 
in the same way that the three terminals mentioned 
above were connected. 

If the coil is separate from both the magneto and the 
switch it may have either three or five terminals, de- 































Section 5 
60 


IGNITION 


pending on whether the battery is grounded or not 
grounded, respectively. In either case the largest and 
heaviest terminal is the high tension and should be 
connected to the extra terminal on the distributor. 

If this leaves two terminals on the coil either one 
is to be connected to the breaker terminal on the mag¬ 
neto and the other one to the switch. Connect one to 
the breaker and the following instructions will tell 
which switch terminal to use. 

If there are four terminals on the coil box after con¬ 
necting the high tension, touch the ends of the tester 
to two of them at the same time until you find the two 
that light the lamp the brightest or show the greatest 
flow through an ammeter. Connect one of these to one 
of the battery terminals and the other one to the 
ground terminal on the magneto. This leaves two 
terminals on the coil and either one may be connected 
to the breaker terminal of the magneto, the other one 
being connected to the switch as directed below: 

When the coil is separate there will of course be a 
separate switch with either three or five terminals on 
this switch. If there are five terminals find two of 
them that always make a complete circuit no matter 
in what position the switch is placed. Connect one 
of these terminals to the battery terminal not grounded 
or connected to the coil and connect the other one of 
these two terminals to the ground terminal on the 
magneto. Now turn the switch to the battery posi¬ 
tion and find two terminals that complete the circuit 
but that break it when the switch is moved from the 
battery position. Mark these two terminals red. Now 
move the switch to the magneto position and find two 
terminals that make a circuit when the switch is this 


IGNITION 


Section 5 
61 


way but that break the connection when the switch is 
moved and mark these two blue. Connect the termi¬ 
nal that has both a red and a blue mark to the terminal 
of the coil mentioned above that was connected to the 
switch, connect the terminal with the red mark only 
to the remaining terminal of the battery and connect 
the one with the blue mark only to the armature termi¬ 
nal of the magneto. 

If the switch has only three terminals it will only 
be necessary to test for the terminals that were marked 
red and blue, the others not being on the switch. 

It should be remembered that the above instructions 
will not take care of every case and that it is always 
best to proceed according to the markings on the mag¬ 
neto, coil and switch when there are any markings to 
go by. If you have a wiring diagram it is best to use 
it, but if you do not get the proper results you can 
perform the above tests and make the connections 
accordingly. 



SINGLE SPARK BATTERY IGNITION. 


Single sparkers are really a form of breaker used in 
connection with a battety and transformer coil for 
ignition. 

They differ from the vibrator used with some coils 
in that they are carried in a separate case like a timer 
and are mounted on the end of some shaft that turns 
at the same speed as a magneto shaft would turn for 
the same engine. They are operated by cams and 
produce only one spark at each ignition point. They 
act in somewhat the same way as the breaker of a 
magneto except that by using a special form of cam 
and spring the break is made extremely quick, produc¬ 
ing a powerful, hot spark with very little battery cur¬ 
rent consumption. The best known makes are the 
Atwater Kent and the Briggs and Stratton. 

The adjustment and care required are the same as 
for magneto breakers, the adjustment being secured 
by turning one of the platinum contact points closer to, 
or farther from, the other one. The adjustable point is 
carried on the end of a screw which may be turned 
either way. 

Should the sparker refuse to spark properly the most 
probable cause of trouble is that the contacts are dirty, 
worn, pitted, rough, or, that they do not meet each 
other squarely. They should be carefully dressed with 
a small flat file so that the points are clean and meet 
each other smoothly. 

After dressing them the points should never touch 

62 


IGNITION 




Fig-. 11.—Contact 

A—Notched Shaft. 

B—Contact Spring. 

C—Condenser. 

D—Lifter. 


maker disassembled. 

E—Lifter Spring. 

F—Contact Arm. 

G—Contact Arm Spring, 
H—Contact Screw. 


Section 5 

63 


UNISPARKER. 





IGNITION 


Section 5 

64 

each other when the engine is idle and the gap between 
the points should be from l/64th to l/32nd inch. The 
smaller the gap the more battery current will be used 
but the spark will be hotter. The points should be 
separated as much as possible and still allow the spark- 
er to operate properly. 

Should the batteries become weak the engine may be 
made to run for a short time by screwing the points 
nearer together. 

A single sparker is mounted on a revolving shaft 
and fastened by set screws in such a position that a 
spark is produced just after the piston starts down on 
the firing or power stroke with the sparker moved as 
far as possible in the same direction that the shaft runs, 
in other words, retarded. 

Single sparkers come complete with their coil and 
with a distributor mounted on the sparker if the engine 
has more than two cylinders. The coil is usually 
mounted on the dash of the car and may carry the 
switch. The wiring is done according to the marks 
at the terminals of each part. 




SPARK ADVANCE AND RETARD. 


It would seem that a flame travels exceedingly fast, 
yet the flame through the gasoline vapor in the cylin¬ 
der travels slowly compared to the speed of the piston 
when the engine is running fast. For this reason it is 
necessary to make the spark pass between the points 
of the spark plug before the piston has come to the top 
of its stroke if the engine is running fast. By the time 
the flame spreads from the end of the plug through the 
gas and has produced the pressure to drive the piston 
down on the power stroke, the piston will have come to 
the top of its stroke. If the spark was not advanced 
enough the piston will have already started down 
again. 

Means are always provided for causing the spark to 
pass at the plug earlier in the stroke, this being ad¬ 
justable by the driver while the engine is running in 
most cases though not adjustable by the driver in other 
types. 

Whenever there is means for changing the time of 
the spark it must be caused to come late in the stroke 
when*the engine is being cranked *by hand to avoid 
danger of the piston starting back the wrong way and 
injuring the operator. To retard the spark in this way 
it is necessary to turn the timer, magneto breaker, 
single sparker or distributor in the same way that their 
driving shaft turns just as far as the levers will allow 
them to go. 

In setting these devices they should cause the spark 

65 


IGNITION 


Section 5 

66 

to come just after the piston starts down on the power 
stroke when the instrument is fully retarded as de¬ 
scribed above. 

The single exception to this rule is with a true high 
tension magneto with which the engine may easily 
be started by cranking rapidly with the switch in the 
magneto position, making it unnecessary to use the 
battery system even for starting. In this case the spark 
lever should be advanced more than half way and al¬ 
most two-thirds of its whole travel. 

There is no danger of a back kick for the reason that 
no spark will be generated in the magneto until the 
crank shaft speed is great enough to carry the piston 
over top center and down onto the power stroke. 

Set spark systems have no way for the driver to 
change the advance or retard of the spark while run¬ 
ning. This system is only used when a high tension 
magneto is the only means of ignition, it would not be 
safe with battery ignition of any kind. There is no arm 
on the breaker and the breaker cover will not turn 
around the armature shaft. This type of magneto 
should be set to cause the points to separate and the 
spark to occur when the piston is coming up on the 
compression stroke and from fifteen to thirty degrees 
(on the flywheel) before the piston reaches top center. 

The slow burning of the gas in the cylinder has 
caused several makers to adopt the Two Spark Ignition 
system in which two separate sparks are caused in dif¬ 
ferent places in the cylinder at exactly the same time 
so that the flame may start from two places at the 
same time and complete the ignition quicker. 


SPARK GAP. 


Safety. Should the spark plug wire become loose or 
broken while the spark current is being generated in 
the secondary winding of any transformer coil this high 
voltage current does its best to escape in some way. 
This may break through the insulation of the wires in 
the coil and put the coil out of business. 

It is not safe to make a spark jump a space in the 
air of more than one-fourth to three-eighths of an inch, 
anything more than this may cause the current to break 
through the insulation inside the coil. To prevent dam¬ 
age to the coil in such cases all high tension magnetos 
and many single unit non-vibrating transformer coils 
are equipped with a safety spark gap. This consists of 
two points separated by about one-fourth to three- 
eighths of an inch, one point being grounded and the 
other one connected to the high tension circuit. In 
case one of the high tension wires should become dis¬ 
connected the current will jump this gap and escape 
to the frame without doing any damage. 

On a coil the safety gap is usually on the top or at 
one end, on a high tension magneto the safety gap will 
be connected to the bar or wire going from the high 
tension collector terminal. 

Never, under any conditions, alter a safety gap in 
any way. 

Auxiliary. It is claimed that a dirty or sooted plug 
may be caused to spark properly if the wire leading to 
the plug is separated from the end of the plug by about 

67 


32 


IGNITION 


Section 5 

68 

one-sixteenth inch, causing the spark to jump this out¬ 
side gap before jumping the gap between the spark 
plug points. 

The theory is that the current gradually escapes in 
a dirty plug by leaking along the coat of soot that 
covers the insulation. This gradual escape lowers the 
voltage of the current so that it cannot jump the spark 
gap in the plug at the proper time. 

By having an outside gap it is claimed that the cur¬ 
rent is held back and prevented from flowing by this 
extra gap until its voltage becomes so high that it is 
forced across the spark plug points, not taking time 
to leak over the soot. 

Auxiliary spark gaps are made in permanent form 
and sold by supply houses for attachment to the plugs. 
They are composed of two points separated by one- 
sixteenth inch and enclosed in a small glass or mica 
tube. This tube is closed at each end and has means 
for fastening to the plug and to the wire. 

An auxiliary gap is very handy in locating missing, 
as it shows positively when the spark is passing in any 
plug. 


SPARK PLUGS. 


The ordinary spark plug consists of a short steel 
tube or shell which is threaded on the outside so that 
it may be screwed into the cylinder or valve cap. A 
wire carries the current down through the center of 
the plug, this wire (called the central electrode) is car¬ 
ried in an insulating bushing made from porcelain, 
stone or mica. This insulating bushing fits into the 
outside shell and is made a gas tight fit by packing the 
joint with asbestos cord or a copper asbestos gasket. 
The gaskets are held tight and the insulation is kept in 
place by a small packing nut around the insulation. 
This nut screws into the top of the shell. 

In cleaning a plug it is best, if possible, to unscrew 
this packing nut, being very careful not to break the in¬ 
sulation, and then remove the insulating bushing which 
carries the central electrode. The surface of the in¬ 
sulation may then be wiped with a cloth dampened in 
gasoline or may be rubbed clean with a stiff brush. 
The insulation must be clean both above and below 
the place where it passes through the shell. The spark¬ 
ing points should be cleaned with a small file or piece 
of emery cloth. 

In putting a plug back together make sure that after 
it is assembled the points across which the spark jumps 
are apart the thickness of a dime for battery ignition 
and the thickness of a business card for magneto igni¬ 
tion. It is a mistake to suppose that a stronger spark 
is produced by having the points farther apart, just 

69 


IGNITION 


Section 5 

70 

the reverse being true. Screw the packing nut just 
tight enough to make a good joint; screwing it tighter 
will make porcelain insulation crack as soon as the 
engine heats up. Make sure that the small lock nut 
and washer at the top of the central electrode is screwed 
tight because this prevents the electrode from getting 
out of place after adjusted. If the plug has a rather 
coarse tapered thread it is not necessary to use any 
gasket or packing when screwing it into the engine, but 



BERGIE NATIONAL SPARK PLUG 

l 

One of the newest types. The noteworthy feature of this plug is that 
it throws a flame one inch long into the explosive mixture. There are 
three members in the lower end of the plug which look like rods. A flattie 
of fire—electricity—passes from the entire length of the center rod in both 
directions to the two outside rods. This gives an intense firing flame. 

if the plug has a straight thread, with more threads to 
the inch, a copper asbestos gasket must be placed so 
that it comes between the edge of the plug hole and 
the flange around the shell just above the threads. 
Plugs are made with three different threads, one-half 
inch standard, A. L. A. M. standard and metric. Al¬ 
ways make sure that the plug is the right size for the 
hole you are placing it in. 


IGNITION 


Section 5 

71 


Porcelain is the commonest insulation and the cheap¬ 
est. Its greatest fault is that it cracks comparatively 
easily under heat or if hit. It is very durable, outside 
of these points and is easily cleaned when sooted. 

Mica forms an insulation almost unaffected by ac¬ 
cidental blows or extreme heat, the greatest objection 
being that oil finally works through between the layers 
of mica and forms, a short circuit for the spark current. 

Stone or lava makes a very durable and almost in- 



SPARK PLUG WITH A. L. A. M. STANDARD THREAD. 

destructible insulation, but little affected by heat, oil 
or accident. 

Two or more of these insulating materials are often 
used in combination, one being outside or above or 
below the other. 

There are countless designs and types of plugs on 
the market but they may all be classified according to 
the thread, the insulation and the length of the shell. 
The y 2 inch standard thread is an ordinary tapered 



IGNITION 


Section 5 

72 

pipe thread cut on the outside of a tube or pipe having 
a Yz inch inside diameter. There are fourteen threads 
to the inch, a taper of % inch to the foot, the outside 
diameter being 84/100ths of an inch. It is the only- 
tapered thread in use and may be easily recognized in 
this way. 

The A. L. A. M. standard is often called a %-18 plug 
because of the fact that the threads are cut on the out¬ 
side of a tube having an outside diameter of %ths inch 
and has 18 threads to the inch. It has no taper. 

A metric thread is cut on the outside of a tube having 
an outside diameter of % inch with the number of 
threads measured according to the metric system. It 
is seldom found except in a few motorcycles and the 
oldest American cars and in foreign makes. 

Sometimes the distance from the outside of the cyl¬ 
inder or cap into which the plug is screwed to the 
combustion chamber is greater than with other types. 
The points across which the spark jumps, should ex¬ 
tend into, or at least to, the combustion space and to 
make this possible plugs are made'in four lengths. 
The ordinary plug, which is delivered unless ordered 
otherwise, has a shell about one inch long in the thread. 
This fits the majority of engines. A short plug has 
only about % inch of thread, a long plug has about 1% 
inch screwing into the cylinder and an extra long plug 
has an extension about 2 inches below the thread. 

Spark plugs may be located in the valve caps, in the ' 
side of the cylinder wall or in the cylinder head. The 
valve cap is the commonest location. When the valve 
cap is used it is customary to place the plug most used 
(usually the magneto) over the inlet valve where it 
receives the fresh gas, although many engines will 


IGNITION 


Section 5 

73 

throttle slower if the plug is over the exhaust. The 
plug over the exhaust soots easier than the one over 
the inlet and if the plug that is used is placed here its 
continual firing tends to keep it clean, but if the idle 
plug is over the exhaust there is nothing to prevent its 
sooting to such an extent that it will not work when 
wanted. 

A new form of plug has been marketed that makes it 
possible to use two plugs in each cylinder both spark¬ 
ing at the same time from one spark source. This 
gives many of the advantages of the two spark ignition 
without its expense. 

The old plug is left in place but its wire is removed. 
The special two point plug is made with two elec¬ 
trodes passing through the insulation in place of only 
one as in the ordinary plug. There are two terminals 
on top of the plug, one for each electrode. The spark 
wire is fastened to one of these terminals and then a 
short wire is fastened from the other terminal to the 
top of the old plug. The spark will now come to the 
special plug, down through one electrode and jump 
the gap to the other electrode. It will then pass up 
the other electrode and across the short wire and 
through the old plug and to the ground. This causes 
two sparks at the same time, the sooting or short cir¬ 
cuiting of one plug having little effect on the other, 
although the added resistance of the extra gap requires 
that the points be close together in both plugs. 

Spark plugs are made in many special forms, among 
them being plugs with a priming cup and pet cock in 
the shell. An engine without means for placing liquid 
gasoline in the cylinder for easy starting may have 
these plugs fitted so that the engine may be primed 
with gasoline for starting. 


IGNITION 


Section 5 

74 

Other forms of plugs are made to be easily removed 
for cleaning by having a special thread and a handle 
so that by twisting the handle a quarter or half turn 
the center of the plug may be taken out. 

Spark Plug Troubles. 

1. Points have dirt, oil, or water between them. 
Clean with emery cloth. 

2. Points too far apart. With magneto ignition the 
points should be the thickness of a business card apart, 
with batteries the thickness of a dime. 

3. Points burned off. Clean and adjust. 

4. Points touching. Separate as told above. 

5. Points ash-colored. Clean with emery cloth. 

6. Points loose. New plug. 

7. Insulation dirty. Clean with gasoline and a cloth, 
or with a wire brush, or by soaking in acetic acid. 

8. Porcelain cracked. New porcelain. 

9. Mica insulation oil-soaked. New mica core. 

10. Insulation core loose in the shell. Tighten the 
packing nut slightly. 

11. Insulation wet, or covered with grease or paint. 
Must be clean and dry. 


WIRING. 


Wires are made from stranded or braided copper. 
The copper is covered with a layer of rubber, cotton 
or silk to insulate the current and protect the wires 
from the atmosphere and moisture. The insulation 
may be composed of rubber alone or of rubber with 
either cotton or silk covering, the amount or thickness 
of the insulation being suited to the current carried. 
High amperage requires large copper and small in¬ 
sulation, high voltage requires only small wire but 
heavy insulation. 

Duplex and multiple cables have insulating cover¬ 
ings that carry two or more copper conductors in the 
one cover but insulated from each other. This type of 
cable is used where only one line is wanted carrying 
both positive and negative sides of a circuit or several 
circuits, such as lamp wires, wires from the timer to 
the coils, etc. 

High tension wire is understood to be suitable for 
carrying the spark current of 10,000 or more volts. 
This cable for use with magneto current is usually 
covered with rubber only and is from nine thirty- 
seconds to three-eighths of an inch outside diameter. 
Cable for battery current is usually covered with cot¬ 
ton or silk and is from three-eighths to one-half inch in- 
outside diameter. 

Low tension wire has a larger copper conductor 
than the high tension, but, with the insulation com¬ 
posed of rubber and cotton, the outside diameter is 

83 


33 



Section 5 

84 


IGNITION 


only from seven thirty-seconds to nine thirty-seconds 
inches. 

When wires are connected to terminals of electrical 
parts the end of a wire must be fitted into and soldered 
to a special brass or copper or hard rubber covered 
terminal that is designed to attach to the screw or ter¬ 
minal. 

To make a joint between two wires, the ends must 
be scraped free of insulation for about one inch and 
then twisted around each other so that they cannot 
pull apart. This joint must then be filled with solder 
and covered with a layer of rubber tape and then with 
two or three layers of friction tape. 

Wiring Troubles. 

1. Wire disconnected. Look especially at the ground 
wires. 

2. Spark plug wires on wrong. Find the correct 
firing order. 

3. Loose ends on terminals. Should be tightened 
with pliers. 

4. Cover worn off. New wire, or tape the old one. 

5. Wires rubbing against metal. New wire, or tape 
old one and fasten. 

6. Wire broken inside of cover. New wire. 

7. Broken wire or terminals. New wire or terminals. 

8. Wires wet or dirty.. Must be kept clean and dry. 


Alphabetical List of Contents 


Black figures indicate section; light face figures, page in that 
section. 


Accumulator, see Storage Battery. 
Acetylene, see Gas. 

Acid, battery.. 

Adjustment—ball joint . 

bearing, annular . 

cup and cone. 

plain . 

roller .. 

brake . 

carburetor .. 

Breeze . 

Holly . 

Kingston . 

Rayfield . 

Schebler . 

Stromberg . 

Zenith . 

chain . 

clutch, band. 

cone . 

dry plate.. 

multiple disc . 

ignition, see under name of part 

lubricator ..... 

planetary transmission . 

radius rod. 

steering gear.. 

timing gears, see Valve Timing 

transmission gears . 

wrist pin . 

Advance and retard. 

Air intake, auxiliary. 

primary . 

A. L. A. M. Spark plug. 

Alcohol . 


SEC. PAGE 


.. 4—82 
.. 1—11 
.. 1—15 
.. 1—17 
.. 1—18 
.. 1—26 
.. 1—28 
.. 1—40 
.. 1—45 
.. 1—47 
.. 1—48 
.. 1—49 
.. 1—53 
.. 1—61 
.. 1—64 
.. 1—78 
.. 1—85 
.. 1—87 
.. 1—90 
.. 1—91 

.. 1—142 
.. 1—188 
.. 1—153 
.. 1—169 

.. 1—142 
.. 1—229 
5 — 4 , 65 
.. 1—39 
.. 1—39 
. . 5—72 
.. 2—3 


513 


































514 INDEX 

SEC. PAGE 

Alternating current .3—8; A —22 

Ammeter.3—15; A —9 

connecting ... A —73 

indicator .'. A —9 

reading. A —28, 135 

Amperage . 3—13 

of dry cells.5—18, 21, 22 

of lamps . 4—57 

Ampere . 3—13 

hours .3—13; A —29, 81 

regulation, see Regulation 

turns .. 3—23 

Annular ball bearings, see Bearings 

Anti-freeze mixtures ..1—93; 2—3, 13 

Armature . 4—16 

core .4—23, 43 

magnet . 3—19 

magneto .4—34-43 

shaft . A —43 

tunnel . A —21 

winding .4—21, 42; 5—6 

Assembling, see under name of part 

Attraction, magnetic..3—18 

Atwater-Kent ignition . 5—52 

Auxiliary air intake or valve .1—39-68 

spark gap . 5—67 

springs .:.1—164 

Axle ... 1—3 

camber ... 1—3 

front . 1—3 

full floating.1—5, 9 

rear . 1—5 

semi-floating . 1—5 

three-quarter floating. 1—5 

Babbitt bearings . 1—17 

Ball bearing, annular . 1—13 

cup and cone. 1—16 

lubrication ..1—14, 17, 18, 26 

Ball and socket joint . 1—11 

Bar, commutator .4—23, 26 

magnet . 3—18 

Base, dynamo . A —39 

lamp . 4—58 

magneto . 5—42 

Battery .. 3—6 

charging, see Storage Battery 

connectors . 5 —20 

dry, see Dry Cells 

Edison .... 3 — 8; A —95 

ignition, see Ignition 














































INDEX 


Battery 

storage, see Storage Battery 

testing ... 

Bayonet lamp base. 

Bearing, annular ball. 

armature shaft . 

cam shaft....... 

cup and cone. 

plain . 

roller . 

scraping . 

wrist pin. 

Benzol . 

Block chains . 

Body polish . 

Box, junction . 

Brake adjustment . 

electric . 

emergency . 

facing of lining. 

service . 

transmission brake . 

Breakage, see under name of part 

Breaker . 

point care. 

timing, magneto. 

vibrating . 

Breeze carburetor . 

Bronze bearings. 

Brush, distributor . 

dynamo . 

holder . 

insulation . 

motor .'. 

pig tail . 

springs . 

Bucking coil . 

magnets . 

regulation . 

Buick, Dave, carburetor . 

Building up of dynamo. 

Bulbs, see Lamps 

Burner, gas . 

Cable, see Wires 

Calcium carbide . 

Cam shaft bearings. 

adjustment . 

Cams . 

Camber of wheels . 

Candelabra lamp base. 

Candlepower of lamps. 


515 

SEC. PAGE 


3—14; 4—84, 92, 99 

. 4—58 

. 1—13 

. 4—43 

. 1—35 

. 1—16 

. 1—17 

. 1—25 

. 1—21 

.1—229 

. 2—5 

. 1—77 

. 2—18 

. 4—12 

. 1—28 

.. ..4—130 

.. 1—28 

. 1—30 

.. 1—28 

. 1—33 

.5—3, 62 

. 5—5 

. 5—46 

. 5—81 

. 1—45 

. 1—17 

. 5—24 

.4—16, 23, 45 

.4—26, 46 

.4—26, 46 

.4—16, 23, 45 

. 4—26 

..4—27, 46 

.4—34, 121 

. 4—21 

.4—34, 121 

. 1—52 

. 4—31 

. 2—6 


2—5 

1—36 

1—37 

1—35 

1—3 

4—59 

4-54 
















































516 INDEX 

SEC. PAGE 

Cantilever spring.1—164 

Carbide, calcium . 2—5 

Carbon lamp bulbs . 4—57 

Carburetor . 1—38 

adjustment . 1—40 

assembling. 1—65 

design . 1—38 

fuel feed .1—132 

heating . 1—69 

piping ... 1—138 

troubles .1—43, 65, 66 

Care, see under name of Part 

Cartridg-e fuse. 4—64 

Castor oil. 2—7 

Cells, dry, see Dry Cells 

. storage, see Storage Battery 

Centrifugal cut-out .4—102 

Chain . 1—77 

adjustment . 1—78 

broken . 1—79 

lubrication . 1—77 

size . 1—80 

wear . 1—79 

Chalk . 2—76 

Change speed, see Transmission 
Charging, battery, see Storage battery 

indicator .4—109 

Circuit . 4—51 

broken... 4—51 

short . 4—72 

tester . A —70 

tracing . 4—72 

Clicking noises .1—150 

Clincher tires and rims.1—172 

Clutch . 1—81 

band . 1—85 

cone . 1—86 

dry plate.• •. 1—89 

facing . 1—30 

location . 1—81 

multiple disc. 1—91 

overrunning. 4—48 

removal ... 1—81 

Coil, battery . 5—6 

bucking, see Bucking coil 

induction . 3—24 

master vibrator.. .. 5—7 

multiple unit . 5—12 

single unit . 5—H 

spark.5_6, 29 

step up . 3 —24 















































INDEX 


517 


Coil 

transformer . 

vibrator .. 

wiring, magneto.. 

Combined unit system. 

Combustion . 

Commutator, battery, see Timer 

dynamo or motor .. 

segments . 

Compound field regulation. 

magnet .. 

winding . 

Compression . 

stroke . 

Concentric float . 

Condenser . 

Conductor. 

Cone clutch . 

Connecting rod . 

bearing adjustment .. 
eight cylinder types ., 

Connections, battery . 

lamp . 

Connectors, battery . 

Constant armature speed. 

driving power.• •. 

Construction, see under name of parts 

Contact breaker . 

point care . 

Contracting band clutch.. 

Control, dynamo, see Regulation 

spark and throttle • .. 

Cooling system . 

troubles . 

Core, armature .. 

field . 

Cork, ground. 

Counterbalanced crankshafts . 

Coupling, Oldham . 

Cracked cylinder . 

Cracks, see under name of part 

Crank shaft . 

bearings . 

adjustment. 

types . 

Cup and cone ball bearings. 

Current, alternating . 

direct . 

electricity . 

flow . 

indicators . 


SEC. PAGE 

...3—24; 5—6 

. 5—81 

.5—52 

. 4—15 

. 1—69 

..4—16, 23, 43 

.4—23, 26 

.4—121 

.3—19 

.4—34, 37 

1—94, 135, 155 

. 1—94 

. 1—40 

. 1—13 

. 2—5 

. 1—86 

.1—97 

. 1—18 

.1—118 

. 3—9 

. 3—9 

.. 5—20 

.4—126 

.4—126 


. 5—3 

. 5—15 

.1—78, 85 

.1—159 

.1—100 

.1—101, 102 

.4—23, 43 

. 4—47 

.. 2—8 

.1—108 

. 5—35 

.1—113 

.1—111 

.1—111 

. 1—18 

.1—108 

. 1—16 

.3—8; 4—22 

. 3—9 

. 3—4 

3—5, 8, 13; 4-51 
. 4—9 
















































518 


INDEX 


Current SEC * PAGE 

measurement .3—12, 14; 4—9 

output of dynamo .4—27, 29, 112 

path . 4—51 

regulation, see Regulation 

sources . 3—5 

Cut-out .4—8, 101 

adjustment . 4—10 

centrifugal .4—102 

electro magnetic.4—105 

hand operated.4—101 

indicators .4—109 

mercury switch.4—104 

opening and closing . 4—10 

Cycle ...1—234 

four ..1—234 

two .1—200 

Cylinder .1—112 

cracked .1—113 

removal and replacement.;.1—112 

scratched .1—113 

Demountable rims.1—173 

Denatured alcohol . 2—5 

Design, see under name of part 

Differential gears ..1—115 

piston engine .1—205 

winding, see Bucking Coil 

Direct current. 3—9 

Direction of flow. 3—8 

Disc clutch. 1—91 

Distribution panel... 4—13 

Distributor .5—23, 47, 79 

timer .5—25, 79 

firing order . 5—24 

wiring .5—45, 47 

Double ignition .5—52, 27 

point ignition .5—73, 75 

row annular bearings .1—14 

wire system . 4—61 

Dressing, body . 2—18 

top . 2—20 

Drive, dynamo or motor...4—47 

magneto . 5—35 

Driving chains .... 1—77 

Dry Cell .3—6; 4—17 

amperage . 4—18,21,22 

connecting . 4—20 

construction .4—17; 3—6 

restoring . 4—19 

voltage .. 4—18 
















































INDEX 


519 


Dry plate clutch. 

Dual ignition . 

magneto wiring. 

Duplex ignition . 

magneto wiring . 

wire . 

Dynamo . 

action. 

armature, see Armature 

assembling.. 

brushes . 

care . 

commutator .. 

control, see Regulation 

drive . 

fields . 

mounting . 

Dynamotor . 


SEC. PAGE 

. 1—89 

.5—27, 56 

.5—53, 56 

. 5—28 

. 5—54 

. 5—83 

.4—7, 16, 39 

. 4—16 

. 4—40 

.4—23, 45 

.4—39, 41 

.4—23, 43 

. 4—47 

.4—16, 19, 30, 47 

.•. 4—39 

.4—14, 38 


lEdiswan lamp base. 

Edison battery . 

Efficiency of lamps. 

of storage battery. 

Eight cylinder engines . 

firing orders 
Electric, see name of part or thing 

Electricity, kinds of. 

Electrolyte, battery . 

Electro.-magnet . 

polarity . 

strength . 

series connected . 
shunt connected .. 

Electro-magnetic cut-out . 

regulators 

Engine, four cycle. 

two cycle . 

eight cylinder . 

twelve cylinder. 

Engine primers. 

Exhaust manifold . 

stroke . 

Expanding band clutch . 

Explosion stroke . 

Extra air intake . 

long spark plug . 


.4—58 

3—8; 4—95 

. 4—56 

.4—82 

.1—117 

.1—118 


. 3—3 

4—77, 79, 82 

. 3—21 

. . ..3—21, 22 

. 3—23 

.4—105 

.4—105 

.4—105 

.4—113 

.1—233 

.1—200 

.1—117 

.1—120 

. 1—75 

.1—120 

.1—233 

. 1—85 

.1—233 

.... 1—39, 68 
. 5—72 


Facing, brake and clutch 

Feed, fuel. 

Fibre grease . 


1— 30 
1—132 

2— 13 


















































520 


INDEX 


Field . 

core . 

current regulation, see Regulation 

magnets . 

permanent magnet . 

winding. 

bucking coil . 

characteristics . 

compound . 

differential . 

series . 

shunt . 

Filament, lamp . 

Fire point of oil. 

Firing orders . 

point . 

Fitting, see under name of part 

Flash point of oil .. 

Flax . 

Float ... 

chamber . 

concentric . 

level . 

lever . 

valve .. 

Flow, current.. 

direction of . 

Fly wheel . 

Ford carburetor adjustment. 

clutch . 

magneto . 

ignition . 

transmission . 

valve timing . 

Four cycle engine. 

magneto . 

Four pole electric machines. 

Frame, straightening . 

Friction transmission .. 

Front axle . 

Fuel, alcohol . 

benzol . 

feed . 

gasoline . 

kerosene . 

Full elliptic spring. 

floating axle .. 

Fuse . 

box . 


SEC. PAGE 

3—17; 4—16, 19, 30 
. 4—47 

. 4—19 

.4—19 

.4—19, 30, 47 

. 4—34 

. 4—35 

.4—34, 37 

. 4—34 

.4—31, 35 

.4—32, 37 

.... 4—55 

. 2—17 

.1—124, 127 

.5—46; 1—205 

. 2—16 

. 2—19 

. 1—39 

. 1—39 

. 1—40 

. 1—42 

. 1—39 

. 1—39 

.3—5, 13 

. 3—8 

.1—127 

.1—47, 48 

.1—91 

. 5—41 

....5—7, 12, 77, 81 

.1—186, 187. 

.1—181, 184 

.1—233 

. 5—35 

.4—22 

.1—129 

.1—176, 189 

. 1—3 

. 2—3 

. 2—5 

.1—133 

. 2—8 

. 2—13 

.1—162 

.1—5, 9 

.. .4—12, 62, 64, 73 
.4—65 

















































INDEX 


521 


SEC. PAGE 

Gap, auxiliary spark . 5 _ 57 

safety spark.!!!!'.!'.!!!!! 5 _67 

spark plug point .]. * ] 5—69 

Gas burners . 2 _ 6 

generators . 2 _ 5 

lamps. 2—6 

pipes . 2—6 

tanks . 2—3 

Gasoline . 2 _ 8 

* eed ,...‘ ! 1—132 

for cleaning . .:. 2 _ 10 

joint packing . 2 _ 10 

Gear shift. 1 _ 157 

electric ... 4—133 

Gears, differential . 1 —115 

rear axle . 1 _ 3 

starter .4^48, 128 

timing ...1—136 

transmission, see Transmission 
Generator, electric, see Dynamo 

gas . 2—5 

igniter . A —15 

Glycerine . 2—10 

Governor, cut-out . A —102 

dynamo clutch . A —126 

Grain alcohol . 2 —5 

Graphite . 2 —10 

Grating noise .1—149 

Gravity fuel feed .1—132 

Grease .. 2 —11 

cup . 2—12 

fibre . 2—13 

graphite . 2—13 

mica . 2—14 

non-fluid . 2—13 

transmission . 2—12 

Grid, battery . 4—77 

Grinding noises .1—149 

valves . 1—210 

Grounding wires .4—61, 66 , 72 

Grounds, testing for .4—72 

Half elliptic spring...1—162 

inch spark plug. 5—71 

Hand operated cut-out .4—101 

Heating, carburetor . 1—69 

plugs ....1—72 














































522 


INDEX 


SEC. PAGE 

High tension . 3—27 

distributor, see Distributor 
magneto, see Magneto 

wiring . 5—83 

winding . . . 3—27 

Hissing noises .1—149 

Holder, brush .4—26, 46 

Holley carburetor . 1—47 

Horsepower of starting motor.3—14, 4—128 

Horseshoe magnet ... 3—18 

Hotchkiss drive .1—177 

Hydrometer, battery testing . 4—84 

gasoline testing . 2—9 


Igniter, low tension . 5—30 

Ignition . 5—1 

Atwater Kent.. 5—62 

battery, distributor . 5—23 

master, vibrator . 5—7 

multiple unit coil . 5—12 

requirements . 4—81 

single coil .5—11 

timer .. 5—77 

timer-distributor . 5—79 

vibrator. 5—81 

double .5—27, 52 

dual .5—27, 53, 56 

duplex .5—28, 54 

low tension . 5—29 

magneto, see Magneto 

make and break, see Make and Break 

master vibrator . 5—7 

set spark .5—27, 66 

single .5—27, 52 

single spark .. 5—62 

transformer coil . 5—28 

two point./... .5—66, 75 

variable spark . 5—28 

wires . 5—83 

Indicator, current ... 4—9 

■ cut-out .4—109 

Induction .2—4; 3—24 

coil . 3—24 

Inductor magneto . 5—38 

Inlet manifold...1—138 

stroke .1—237 

Insulation . 3—5 

broken . 4—72 

brush .4—26, 46 

spark plug . 5—71 















































INDEX 


523 


SEC. PAGE 

Inter brush regulation . 4 _126 

pole regulation . 4 —126 

Interrupted field currents. 4 —127 

Interrupter, see Breaker and Vibrator 

Iron magnet . 3 —19 

Joint, ball and socket .. 1—11 

gasoline pipe. 2—10 

universal, see Universal .1—207 

'wire .... 4 —41; 5—84 

Junction box. 4—12 

Keepers, magnet . 3—19 

Kerosene . 2—13 

cleaning . 2—14- 

cooling . 2—14 

decarbonizing . 2—14 

fuel . 2—13 

loosening parts. 2—14 

Kingston carburetor. 1—46 

Knife switches ... A —69 

Knight engine valve timing .1—209, 217 

Knocking .1—148 

K-W master vibrator. 5—7 


Lag in coils . 

Lamps . 

amperage . 

bases . 

candlepower .. 

carbon . 

connections ... 

efficiency . 

filament. 

fuses . 

gas . 

life .. 

pilot . 

size ... 

tantalum . 

tester . 

tungsten . 

voltage . 

wiring . 

Lapping cylinder .. 

shaft bearings . 
Lava spark plugs .. 

Law of Ohm . 

Laying up a battery 


. 5—65 

. 4—53 

. 4—57 

. 4—58 

. 4—53 

. 4—57 

. 4 — 57 , 60 

. 4—56 

. A — 55 

4 — 12 , 62 , 64 , 73 

. 2—6 

. 4—56 

. 4—110 

. 4—54 

. 4—57 

. 4—70 

. 4—57 

. 4 — 56 , 58 

4 — 12 , 51 , 60 , 66 

. 1—113 

. 1—24 

. 5—71 

.. 3—15 

. 4—90 















































524 


INDEX 


SEC. PAGE 

Leak, compression.1—94 

inlet piping.1—137 

oil or grease.1—15, 23, 27 

radiator .2—19 

Life of lamps. A —56 

Lighting.4—3, 51 

and starting. A —3 

batteries, see Storage batteries 

switches. A —67 

wires ..4—12, 51, 66 

Lines of force.3—17 

Lining brakes and clutches..1—30 

Liquid, battery.4—79, 82 

Litharge and glycerine .2—10 

Live axles .1—7 

Location of clutch.1—77 

spark plug .5—72 

Long Spark plugs .5—72 

Loose cams .1—35 

wires . A —71 

Low tension .3—27 

ignition .5—27, 29 

magneto..5—31, 56 

Ford .5—41 

wiring.-.5—56 

make and break, see Make and Break 

Lubricating oil .2—15 

Lubrication .1—142 

ball bearing.1—14, 17 

chain .1—78 

clutch, band.1—85 * 

cone .1—86 

dry plate.1—89 

multiple disc .1—91, 93 

daily, weekly, etc.1—144 

friction transmission .1—192 

plain bearing.1—18 

planetary transmission .1—188 

roller bearing .1—26 

sliding gear .1—178 

steering gear.1—169 

universal joint .1—207 

Machine oil .2—14 

Magnet .3—17 

armature ..3—19; 4—105 

compound .3—19 

electro—see Electro magnet 
field, see Field 

forms of .3—18 















































INDEX 


525 


Magnet 

keepers . 

permanent . 

placing on magneto 

poles . 

Magnetic attraction .... 

Cut-out . 

electricity . 

field, see Field 

force, lines of. 

pole finding. 

poles . 


SEC. PAGE 

. 3—19 

.3—19; 4—106 

.5—38 

3—18, 20, 21; 4—106 

. 3—18 

.4—105 

.3—3, 17 

.3—17,. 20 

. 3—20 

. 3—18 


Magnetism . 

Magnetizing . 

Magneto . 

action . 

armature . 

breaker timing . 

coil wiring .•. 

direction of turning . 

distributor, see Distributor 

drive . 

Ford .. 

four cylinder . 

high tension . 

inductor . 

low tension .. 

lubrication . 

make and break, see Make and Break 

mounting . 

one cylinder. 

safety gap . 

six cylinder • .. 

speed of rotation . 

terminal finding . 

three cylinder... 

timing, armature . 

breaker . 

distributor... 

troubles . 

two cylinder . 

cycle . 

spark . 

wiring, dual . 

distributor .. 

duplex . 

high tension . 

low tension .... 

transformer coil . 


..3—3, 17 
... 3—19 
... 5—34 
... 5—34 
.5—34, 43 
... 5—46 
... 5—51 
... 5—45 

... 5—35 
... 5—41 
... 5—38 
....5—34 
... 5—38 
.5—31, 56 
... 5—42 

... 5—42 
... 5—35 
... 5—67 
... 5—38 
... 5—35 
.5—48, 56 
... 5—35 
... 5—43 
.5—45, 46 
.5—45, 47 
.5—42, 43 
....5—35 
... 5—38 
.5—73, 75 
,... 5—56 
.5—45, 47 

.5—54 

.5—52, 54 
.5—31, 36 
.5—54, 56 















































526 


INDEX 


SEC. PAGE 

Make and Break . 5—29 

advance and retard .5—30, 31. 

care and use . 5—31 

change to high . 5—33 

igniters . 5—30 

timing .5—32 

troubles . 5—32 

Magnetic transmission .1—194 

Manifold, exhaust .1—123 

heating . 1—69 

inlet .1*—140 

Modern inlet .1—138 

Master vibrator . 5—7 

Measurement of current .3—12, 14; A —9 

Mercury switch cut-out. A —104 

Metal polish . 2—18 

Metric spark plug . 5—72 

Mica, flake . 2—14 

spark plug . 5—71 

Miniature lamp bases. A —59 

Mixing chamber. 1—39 

Mixture, see Carburetor Adjustment and Troubles 

Motor-generator .4—14, 38 

Motor, starting (see Dynamo also). 4—13 

care and handling . A —39 

compound wound .4—34, 37 

drive ..4—47, 128 

clutch . 4—48 

power ..3—14; 4—128 

requirements .4—128 

series wound .4—31, 35 

shunt wound . A —32, 37 

Mounting, dynamo or motor .4—39 

magneto . 5—42 

Multiple connection . 3—11 

of cells . 3—11 

of lamps .3—11; A —60 

disc clutch .1—91 

series connection .3—12; 5—22 

unit coil . 5—12 

wires . 5—83 

Neatsfoot oil.. 2—15 

Negative . 3—9 

pole . 3—18 

terminal finding... 3—9 

wire finding. 3—9 

Noisy operation .1—148 

North pole . 3—18 

Nozzle, carburetor .1—36, 38 

Ohm . 3—14 

Ohm’s law . 3—15 




















































INDEX 


527 


SEP. PAGE 

Oil, castor . 2—7 

kerosene ... 2—13 

lubricating . 2—15 

machine . 2—14 

neatsfoot . 2—15 

non-fluid . 2—13 

soap .... 2—19 

Oildag . 2—11 

Oiling, see Lubrication 

Oldham coupling. 5—35 

One cylinder magneto . 5—35 

unit system . 4—14 

wire system . 4—61 

Order of firing.1—118, 124 

Output of dynamo, see Dynamo 
regulation, see Regulation 

Overcharge, battery .. 4—90 

Overrunning clutch.... 4—48 


Paint, tire. 

Panel, distribution. 

Parallel connection... 

cells . 

lamps . 

Path of current. 

Permanent magnet . 

Pet cock spark plug. 

Pig tails, brush . 

Pilot lamp . 

Pins, wrist . 

Pipes, gas. 

Piston, pins . 

ring -fitting ... 

removal and replacement . 

Plain bearings .. 

adjustment . 

Planetary transmission. 

adjustment 
removal . 

Plate clutch . 

Platinum point care .. 

Play in steering gear. 

spark, see Spark Plug 

Points, breaker or vibrator. 

Polarity .. 

magnetic v . 

wires .. 

Pole, magnetic . 

pieces ..:. 


.2—20 

. 4—13 

. 3—11 

. 3—11 

. 3—11 

. 4—51 

3—19; 4—106 

. 5—73 

. 4—26 

.4—110 

.1—229 

. 2—6 

.1—229 

.1—151 

.1—153 

. 1—17 

. 1—18 

...1—179, 186 

.1—188 

.1—189 

.1—89 

. 5—15 

.1—169 

. 5—15 

. 3—9 

.3—17, 20 

...3—9; 4—73 

.3—18, 20 

. 4—20 


34 














































528 


INDEX 


SEC. PAGE 

Polish, body . 2—18 

metal . .. 2—18 

Poppet valve timing .1—209, 202 

Popping noises .1—150 

Porcelain spark plugs. 5—71 

Positive . 3—9 

pole . 3—18 

wire .3—9; A —73 

Pounding noises .1—148 

Power, electrical .3—14; A —128 

loss of .1—155 

stroke .1—233 

pressure, electrical . 3—12 

fuel feed .1—132 

tire ..1—174 

Prest-O-Lite . 2—3 

Primary.3—27 

air intake.1—39 

coil .3—24 

current.3—27 

winding .3—27 

wiring .5—51, 56 

Priming spark plug.5—73 

Progressive transmission.1—179 

Protection of wires.. A —66 

Pump, water.1—101, 102 

Push button switches. A —67 

rod adjustment.1—216 

Quantity of electricity.3—13 

Quarter elliptic spring.1—162* 

Quick detachable tires and rims.1—172 

Radiant electricity.3—4 

Radiator .1—100 

compound .2—19 

shutters .1—102 

Radius rods .1—158 

Rate of flow.. •.3—13 

Rattling noises.1—150 

Rayfield carburetor.1—49 

Reading the ammeter. A —135 

Rear axle.1—5 

bent .1—10 

leaks .1—8 

loose dogs.1—9 

lubrication .1-—7 

noisy.1—7 

Reduction gear, starter.4—128 

Regulation ... A —7, 28, 112 

armature position.4—121 




















































INDEX 


Regulation 

bucking coil . 

common systems. 

compound field winding. 

constant speed. 

constant power. 

current output. 

cut-out .. 

differential field . 

dynamo output . 

electro-magnetic. 

extra brush. 

extra pole . 

large field .. 

pole piece movable. 

reversed field . 

rotating field . 

saturated field . 

„ shunt field . 

voltage . 

Removal, see under name of part 
Repairs, see under name of part 
Replacing, see under name of part 

Relay, cut-out. 

Residual magnetism . 

Resistance, electrical.. 

Retard of spark. 

Reverse current cut-out. 

Reversed field regulation. 

wiring connections . 

Rims, clincher... 

demountable . 

quick detachable. 

straight side. 

Ring, piston . 

Rod, connecting. 

radius... 

torsion . 

Roller bearing adjustment. 

lubrication. 

troubles . 

chains . 

Rotary switches . 

valve timing.. 

Rotating field regulation. 

Safety spark gap... 

Saturated field regulation ......... 

Schebler carburetor . 

Scraping bearings. 

noises . 


529 


.4—121 

.4—127 

.. .4—37, 121 

.4—126 

.4—126 

.4—112 

.4—110 

.4—121 

. . .4—28, 113 

.4—113 

.4—126 

.4—126 

.4—125 

.4—121 

.4—127 

.4—126 

.4—125 

...4—35, 115 
4—7, 27, 112 


... 4 — 8 , 101 

. 4—31 

3 — 5 , 12 , 14 
.... 5 — 4 , 65 
... 4 — 8 , 101 

. 4—127 

. 4—73 

. 1—172 

. 1—173 

. 1—172 

. 1—173 

. 1—151 

. 1—98 

. 1—158 

. 1—176 

. 1—26 

. 1—26 

. 1—27 

. 1—73 

. 4—67 

. 1 — 210 , 222 
. 4—126 

. 5—67 

. 4—125 

. 1—53 

. 1—21 

. 1—149 

















































530 


INDEX 


SEC. PAGE 

Screw lamp bases . A —59 

Searchlight gas.2—3 

Secondary, see High tension 

Segments, commutator . A —23, 26 

Selective transmission .1—179 

Self-aligning bearings.1—14 

Semi-elliptic springs .1—162 

Semi-floating axles .1—5 

Separate coil ignition .5—6 

unit systems . A —15 

Series connection.3—11 

cells.3—11 

lamps .3—11; A —60 

electro magnet . A —105 

-multiple .3—12 

of cells ..3—12 

winding. A —31, 35 

Set spark ignition.5—27, 66 

Seven-eighths elliptic springs.1—142 

Shaft, armature. A —43 

bearing, truing .1—24 

cam.1—36 

crank .1—107 

Shims, bearing ..1—19 

Short circuit, finding. A —72 

tester. A —70 

Shunt ..3—11 

electro-magnet.4—105 

field regulation, see Regulation 

winding . A —32, 37 

Silent chains..1—77 

Single ignition ...5—27, 52, 66 

row annular bearing.1—14 

spark ignition .5—62 

unit coil.5—11 

unit system. A —14, 15 

wire system .4—61 

Six cylinder magneto..5—38 

pole electric machines. A —22 

Size of lamp bulbs. A —54 

Sleeve valve timing...1—209, 217 

Slapping noises .1—149 

Sliding gear transmission .1—179 

Snap switch. A —69 

Soap, oil .2—19 

Soapstone ..2—7 

Solenoid.3—23; A —110 

Sources of current.3—5 

South pole .3—18 

















































INDEX 


531 


Spark advance and retard. ^sec^page 

and throttle control.1—159 

coil .7.7.7.5—6, 29 

gap, auxiliary.5—67 

, safety .5—67 

Plug .5—69 

A. L. A. M.5 72 

cleaning .5—69 

gap .5—69 

gaskets .5_70 

half inch .5_71 

insulation .5_71 

lengths ....5—72 

location .5—72 

metric .5—72 

priming cup .5—73 

sizes .5—71 

threads..5—71 

troubles .5—74 

two point.5—73 

wiring.5—45, 47 

set .5—27 


' timing, see Breaker and Timer 

Sparker, single . 

Specific gravity, battery. 

gasoline. 

Speed of electric current. 

Spitting noises . 

Split bearing, see Plain- Bearings 

Spring ... 

auxiliary . 

bolt . 

bracket . 

brush . 

clips . 

eyes . 

seats .. 

shackles . 

size . 

type .... 

Squeaking noises . 

Starting . 

battery ... 

motor, see Motor and Dynamo 
switches . 


....5—62 
4—84, 89 

.2—9 

....3—13 

...1—150 

...1—162 
...1—164 
.. .1—164 
...1—164 
4—27, 46 
...1—164 
...1—164 
,.. 1—164 
...1—164 
...1—165 
...1—162 
...1—130 
.4—4, 13 
....4—81 

....4—67 


Static electricity. 

Steering gear ... 

joints .... 
looseness . 
lubrication 
wheel adjustment ... 


.3—3 

..1—5, 167 

.1—169 

.1—11, 169 

.1—169 

.1—169 


















































532 


INDEX 


SEC. PAGE 

Step up coil .2—24; 5—6 

Storage battery.3—6; 4—7, 77 

acid .4—79, 82 

capacity .4—29, 81 

care.4—87 

charging.3—7, 29; 4—7, 64, 88, 109, 115 

charge indicator .4—109 

construction .3—7; 4—77 

Edison .3—8; 4—95 

efficiency .4—82 

electrolyte .4—79, 82, 87 

hydrometer.4—84 

laying up.4—90 

liquid .4—79, 82 

size . 4—27 

sulphated .4—90 

testing .4—85, 91 

types .4—81 

voltage .4—82, 96 

Straight side tires and rims.1—153 

Strength of electro magnet.3—23 

Stroke, compression .1—232 

exhaust .1—233 

explosion .• •.1—233 

inlet .1—232 

power ...1—233 

suction .. 1—232 

Stromberg carburetor .1—58 

Suction stroke..1—232 

Sulphated storage battery.4—90 

Sulphuric acid.4—82 

Switches .4—11, 66 

lighting .4—67 

starting .4—66 


Talc, tire.2—7 

Tanks, acetylene gas.2—3 

Tantalum lamp bulbs.4—57 

Tension, high and low.3—27 

Terminal finding.3—9 

magneto .5—48 

Tester, circuit.4—70; 5—53 

Testing, ammeter.3—15; 4—9 

dry cells .5—18 

storage battery.3—15; 4—82, 92 

Thread, spark plug.5—71 

Three cylinder magneto.5—35 

Three port, two cycle engine.1—204 

Three-quarter elliptic spring.1—162 

floating axle .. 1—5 




















































INDEX 


533 


Three cylinder magneto 

unit system. 

wire system.. ” 

Threshing noises . 

Throttle and spark control. 

carburetor . 

stops . 

Timer . 

action . 

and coil ignition. 

-distributor . 

Timing, distributor. 

firing orders . 

gears . 

Knight engine . 

magneto armature.. 

breaker . 

distributor . 

make and break magneto. 

poppet valves . 

rotary valves . 

sleeve valves. 

spark, see Breaker and Timer 

timer . 

valves . 

Tire, clincher. 

quick detachable. 

paint . 

powder . 

pressure . 

straight side. 

talc . 

vulcanizing . 

Top dressing. 

Torsion rod . 

Tracing circuits . 

Transformer coil ....... 

ignition, see Ignition 

wiring. 

Transmission . 

electric gear shift. 

friction . 

leaky ... 

lubrication. 

magnetic . 

planetary . 

sliding gear. 

Trembler, see Vibrator 

Triple wire system . 


SEC. PAGE 

. 4—15 

. 4—62 

. 1—149 

. 1—159 

. 1—39 

. 1—65 

. 5—77 

. 5—78 

. 5—78 

. 5 — 29 , 79 

. 5 — 45 , 47 

. 1 — 118 , 124 

. 1—136 

. 1 — 181 , 189 

. 5—43 

. 5 — 45 , 46 

. 5 — 45 , 47 

. 5—32 

. 1 — 209 , 212 

. 1 — 210 , 222 

. 1 — 209 , 217 

. 5—78 

. 1 — 212 , 217 , 222 

. 1—172 

. 1—172 

. 2—20 

. 2 — 7 , 14 

. 1—174 

. 1—172 

. 2—7 

. 1—223 

. 2—20 

. 1—176 

. 4—72 

. 3 — 24 ; 5—6 

. 5 — 53 , 56 

. 1—177 

. 4—133 

. 1 — 180 , 191 

. 1 — 15 , 27 

1 — 180 , 188 , 192 

. 1—194 

. 1 — 179 , 186 

. 1 — 179 , 180 

. 4—62 


■ 















































534 


INDEX 




SEC. PAGE 

Troubles, axle.1—40 

battery .4—87 

bearing, cup and cone.1—17 

plain .• •.. /.1—24 

roller .1—27 

cams .1—36 

carburetor .1—41, 65 

chains .1—79 

clutch, band .1—85 

cone .1—87 

dry plate.1—90 

multiple disc.1—92 

connecting rod .1—97 

cooling system .1—101, 102 

crankshaft .1—107 

cylinder ..1—109 

engine ...1—148, 155 

exhaust manifold .-1—123 

finding with ammeter.4—28, 135 

tester .4—70 

frame . . .1—129 

friction transmission.1—193 

ignition, see under name of Part 

magneto .5—43 

noisy operation.1—148 

oiling .1—146 

planetary transmission .1—190 • 

power, loss of.1—155 

sliding gear transmissions..1—185 

spark plug .5—74 

spring ...1—165 

sprung engine parts.1—98 

timing gears.1—136 

tire . 1—174 

two cycle.1—175 

valve .1—155, 210 

wheels .1—227 

wiring..5—84 

wrist pin.1—230 

True high tension magneto.5—52, 53 

Truing shaft bearings.1—24 

Tungsten Lamp bulbs.. .4—57 

Tunnel, armature.4—21 

Twelve cylinder engines.1—120 

Two cycle engine.1—195 

magneto .5—38 

cylinder magneto.5—35 

diameter piston engine.1—205 

pole electric machines.4—22 

port, two cycle engine.1—94 



















































INDEX S35 

SEC. PAGE 

Two cycle engine 

spirit ignition. 5 — 73 , 75 

plug .5—73 

unit system. 4 _ 15 

wire system . 4 _61 

Types, see under name of part 


Unisparker . 5 —52 

Units, lighting and starting.;. 4—14 

Universal joint .1—207 

lubrication .1—207 

Uses, see under name of part 

U shaped magnets.3—18 


Vacuum fuel feed .1—133 

Valve .1—209 

grinding . 1—210 

removal . 1—210 

rod adjustment.1—216 

timing . 1 —212, 217, 222 

Knight engine .1—209, 217 

poppet type .1—209, 212 

rotary type .. 1 — 210 , 222 

sleeve type..1—209, 217 

Variable spark ignition.5—28 

Vaseline . 2 —20 

Verdigris removal . A —87 

Vibrator .5 —81 

adjustment .5—82 

master .5—7 

point care.5—15 

Voltage .3—12 

dry cells .5—18, 21 

lamp .4—56 

regulation . A —27 

storage battery... A —82, 96 

Voltaic electricity .3—4 

Voltammeter .3—15 

Voltmeter .3—14, 4— 9 

connecting . A —73 

Vulcanizing .1—223 


Water, battery . 

system, see Cooling 

Watts . 

Wheels . 

fly . 

lining up. 

removing . 

Wheezing noises . 


.4—85 

3—14; 4—128 

.1—227 

.1—127 

.1—169 

.1—227 

.1—149 













































536 


INDEX 


Winding, armature.. 

bucking coil, see Bucking Coil 

electro magnet . 

field, see Field Winding 

primary . 

secondary . 

Wire wheels . 

Wires .. 

bared . 

broken or loose. 

duplex . 

high tension. 

ignition, see Ignition 

lighting .. 

low tension . 

multiple . 

polarity . 

protection . 

Wiring . 

care . 

connections. 

distributor. 

double ignition. .... 

dry cell. 

dual ignition . 

fuses . 

high tension magneto. 

ignition, see Ignition 

lighting. 

low tension magneto. 

magneto . 

master vibrator.. 

multiple . 

series . 

one wire system. 

separate coil magneto. 

single wire system. 

series connection. 

spark plug. 

tester . 

three wire system. 

troubles . 

two wire system. 

Wood alcohol . 

Wrist pins .. 


SEC. PAGE 

.4—21, 42 

..'4—105 

.3—27 

.3—27 

.1—227 

.4—66; 5—83 

.4—72 

.4—71 

.5—83 

.5—83 

. 4—53 

.5—83 

.5—83 

.4—73 

.4—66 

.4—51; 5—83 

.5—84 

.3—9; 4—73 

.5—47 

.5—52 

. 4—20 

.5—53, 56 

.. .4—12, 62, 64, 73 
.5—83 

4—12, 51, 60, 61, 66 

.5—56 

.5—31, 52 

.5—7 

.3—11 

.3—12 

.4—61 

.5—6 

.4—61 

.3—11 

.5—45, 47 

.4—70 

.4—62 

.5—84 

.4—61 

.2—3 

.1—229 


Zenith carburetor 


1—64 












































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